What happened to OPTION when using BMCreateButton to build Subscribe buttons? - paypal

Question

For well over a year I've been running the same code to generate subscribe buttons using the BMCreateButton NVP API. For some reason, this recently stopped working. Here is my current HTTP request, written in ColdFusion. request.setup.paypal references a structure of settings, request.user is an object that defines a user session.
<cfset buttonvars = [
'item_name=Membership',
'src=1',
'currency_code=USD',
'no_note=1',
'no_shipping=1',
'rm=0',
'return=#request.setup.paypal('return')#',
'cancel_return=#request.setup.paypal('cancel_return')#',
'notify_url=#request.setup.paypal('notify_url')#',
'custom=#request.user.getUserID()#'
] />
<cfhttp method="post" url="#request.setup.paypal('host')#">
<cfhttpparam type="formfield" name="USER" value="#request.setup.paypal('user')#" />
<cfhttpparam type="formfield" name="PWD" value="#request.setup.paypal('pwd')#" />
<cfhttpparam type="formfield" name="SIGNATURE" value="#request.setup.paypal('signature')#" />
<cfhttpparam type="formfield" name="VERSION" value="65.2" />
<cfhttpparam type="formfield" name="METHOD" value="BMCreateButton" />
<cfhttpparam type="formfield" name="BUTTONTYPE" value="SUBSCRIBE" />
<cfhttpparam type="formfield" name="BUTTONSUBTYPE" value="SERVICES" />
<cfhttpparam type="formfield" name="BUTTONCODE" value="CLEARTEXT" /> <!--- CLEARTEXT, ENCRYPTED --->
<cfhttpparam type="formfield" name="OPTION0NAME" value="Membership Duration" />
<cfhttpparam type="formfield" name="L_OPTION0SELECT0" value="Monthly Membership" />
<cfhttpparam type="formfield" name="L_OPTION0PRICE0" value="20.00" />
<cfhttpparam type="formfield" name="L_OPTION0BILLINGPERIOD0" value="Month" />
<cfhttpparam type="formfield" name="L_OPTION0SELECT1" value="Annual Membership" />
<cfhttpparam type="formfield" name="L_OPTION0PRICE1" value="200.00" />
<cfhttpparam type="formfield" name="L_OPTION0BILLINGPERIOD1" value="Year" />
<cfloop from="1" to="#arrayLen(buttonvars)#" index="buttonvar">
<cfhttpparam type="formfield" name="L_BUTTONVAR#buttonvar-1#" value="#buttonvars[buttonvar]#" />
</cfloop>
</cfhttp>
When I make this request I receive a failure response back saying "You must specify valid values for the A3, P3, and T3 parameters for a subscription button." This clearly corresponds with the API documentation here:
https://developer.paypal.com/webapps/developer/docs/classic/paypal-payments-standard/integration-guide/Appx_websitestandard_htmlvariables/#id08A6HI00JQU
The documentation clearly states those values are required. This wasn't necessary before, the fact that I was specifying options for some reason I assume overrode this. That is no longer the case however. So I've attempted to add A3, P3 and T3 HTML variables and then received this error: "You can't specify A3/P3/T3 and Option selection for Subscriptions." At that point, I tried removing the option formfields and was able to generate a subscribe button but without the pulldown menu, as expected. I followed up by trying to create an option field by using HTML variables on0, os0, option_select0 and option_amount0 but this had no effect, I saw the same button without the pulldown menu.
So how does one generate a Subscribe button with an option pulldown menu using the BMCreateButton NVP API? I have tried creating one using the button manager without a problem, however I need to pass a custom field and wish to do so with an encrypted button. Right now my example above is using CLEARTEXT just for debugging. Is this possible any more?