Running in to some issues with Tumblr's Theme Parser - tumblr

Question

Below part of a tumblr theme I'm working on and you will notice that I use the {block:PostType} syntax to declare the opening tag of each post, which is a <li> element in an Ordered List. This allows me to not only dynamicly set the li's class based on the type of post but cuts down on the number of times I'm calling the ShareThis JS which was really bogging down the page. This creates a new issue though which I believe is a flaw in Tumblr's parser. Each post is an ordered list with one <li> element in it. I know I could solve this by having each post as a <div> but I really like the control and semantics of using a list. Tumblr gurus? Suggestions?
Sample of code:
{block:Posts}
<ol class="posts">
{block:Text}
<li class="post type_text" id="{PostID}">
{block:Title}
<h2>{Title}</h2>
{/block:Title}
{Body}
{/block:Text}
{block:Photo}
<li class="post type_photo" id="{PostID}">
<div class="image">
<img src="{PhotoURL-500}" alt="{PhotoAlt}">
</div>
{block:Caption}
{Caption}
{/block:Caption}
{/block:Photo}
{block:Photoset}
<li class="post type_photoset" id="{PostID}">
{Photoset-500}
{block:Caption}
{Caption}
{/block:Caption}
{/block:Photoset}
{block:Quote}
<li class="post type_quote" id="{PostID}">
<blockquote>
<div class="quote_symbol">“</div>
{Quote}
</blockquote>
{block:Source}
<div class="quote_source">{Source}</div>
{/block:Source}
{/block:Quote}
{block:Link}
<li class="post type_link" id="{PostID}">
<h2>{Name}</h2>
{block:Description}
{Description}
{/block:Description}
{/block:Link}
{block:Chat}
<li class="post type_chat" id="{PostID}">
{block:Title}
<h2>{Title}</h2>
{/block:Title}
<table class="chat_log">
{block:Lines}
<tr class="{Alt} user_{UserNumber}">
<td class="person">{block:Label}{Label}{/block:Label}</td>
<td class="message">{Line}</td>
</tr>
{/block:Lines}
</table>
{/block:Chat}
{block:Video}
<li class="post type_video" id="{PostID}">
{Video-500}
{block:Caption}
{Caption}
{/block:Caption}
{/block:Video}
{block:Audio}
<li class="post type_audio" id="{PostID}">
{AudioPlayerWhite}
{block:Caption}
{Caption}
{/block:Caption}
{block:ExternalAudio}
<p>Download</p>
{/block:ExternalAudio}
{/block:Audio}
<div class="post_footer">
<p class="post_date">Posted on {ShortMonth} {DayOfMonth}, {Year} at {12hour}:{Minutes} {AmPm}</p>
<ul>
<li><a class="comment_link" href="{Permalink}#disqus_thread">Comments</a></li>
<li><script type="text/javascript" src="http://w.sharethis.com/button/sharethis.js#publisher=722e181d-1d8a-4363-9ebe-82d5263aea94&type=website"></script></li>
</ul>
{block:PermalinkPage}
<div id="disqus_thread"></div>
<script type="text/javascript" src="http://disqus.com/forums/kyleetilley/embed.js"></script>
<noscript>View the discussion thread.</noscript>
{/block:PermalinkPage}
</div>
</li>
</ol>
{/block:Posts}

Answer 1

The Posts block is executed once for each post, thus the markup for the container should go outside this block.
Just put the <ol> right before {block:Posts} and the </ol> directly after the {/block:Posts}

Answer 2

Try this, it worked for me when I put it into the Theme Parser. I've modified your code a little bit:
overhauled your syntax to be intended. Please don't take offense, I only did it for clarity's sake!
move the <ol> element outside of the {block:Posts} as everything inside it is rendered once for each type of post.
moved and modified your <li> element so that's no longer specific to the type of post, Tumblr provide a neat little {PostType} variable that will print each post's type (except for photoset; for which it prints "photo", but I've added a little bit more in there to account for that.) This is faster to render and simpler to read.
swapped your {AudioPlayerWhite} to {AudioPlayer}, this is just because Tumblr sometimes gets upset if you define the audio player's colour, and a message is displayed on tumblr.com/new/audio saying "Your theme does not support proper audio players". Probably not connected to the problem but it's a good practice
Working example: stackoverflow-theme-test-1.tumblr.com - ignore how it looks because I didn't apply any styling, but the code is all perfectly valid.
<ol class="posts">
{block:Posts}
<li class="post type_{PostType}{block:Photoset}set{/block:Photoset}" id="{PostID}"> <!--Saves you from having to manually define each type of post-->
{block:Text}
{block:Title}
<h2>{Title}</h2>
{/block:Title}
{Body}
{/block:Text}
{block:Photo}
<div class="image">
<img src="{PhotoURL-500}" alt="{PhotoAlt}">
</div>
{block:Caption}
{Caption}
{/block:Caption}
{/block:Photo}
{block:Photoset}
{Photoset-500}
{block:Caption}
{Caption}
{/block:Caption}
{/block:Photoset}
{block:Quote}
<blockquote>
<div class="quote_symbol">“</div>
{Quote}
</blockquote>
{block:Source}
<div class="quote_source">{Source}</div>
{/block:Source}
{/block:Quote}
{block:Link}
<h2>{Name}</h2>
{block:Description}
{Description}
{/block:Description}
{/block:Link}
{block:Chat}
{block:Title}
<h2>{Title}</h2>
{/block:Title}
<table class="chat_log">
{block:Lines}
<tr class="{Alt} user_{UserNumber}">
<td class="person">{block:Label}{Label}{/block:Label}</td>
<td class="message">{Line}</td>
</tr>
{/block:Lines}
</table>
{/block:Chat}
{block:Video}
{Video-500}
{block:Caption}
{Caption}
{/block:Caption}
{/block:Video}
{block:Audio}
{AudioPlayer} <!--Tumblr don't like you to specify a colour for the {AudioPlayer}, you could do anyway, but in the interests of minimising parsing errors I havent-->
{block:Caption}
{Caption}
{/block:Caption}
{block:ExternalAudio}
<p>Download</p>
{/block:ExternalAudio}
{/block:Audio}
<div class="post_footer">
<p class="post_date">Posted on {ShortMonth} {DayOfMonth}, {Year} at {12hour}:{Minutes} {AmPm}</p>
<ul>
<li><a class="comment_link" href="{Permalink}#disqus_thread">Comments</a></li>
<li><script type="text/javascript" src="http://w.sharethis.com/button/sharethis.js#publisher=722e181d-1d8a-4363-9ebe-82d5263aea94&type=website"></script></li>
</ul>
{block:PermalinkPage}
<div id="disqus_thread"></div>
<script type="text/javascript" src="http://disqus.com/forums/kyleetilley/embed.js"></script>
<noscript>View the discussion thread.</noscript>
{/block:PermalinkPage}
</div>
</li>
{/block:Posts}
</ol>