Grails Plugins Import failing after using new mavenCentral() secure HTTPS Libraries - import

Question

After Sonatype, the hosts of the Maven Central stopped permitting insecure connections to their repository via http I started getting issues resolving the dependencies. I was able to overcome that by adding the following to my BuildConfig.groovy file:
mavenRepo "https://repo.grails.org/grails/plugins/"
mavenRepo "https://repo1.maven.org/maven2/"
mavenRepo "https://repo.grails.org/grails/core"
mavenRepo "https://oss.sonatype.org/content/repositories/releases/"
--
My issue now is every import inside the plugin below is failing and not sure why. Getting this error:
--- this is just a snippet of the errors but is the same for every import ---
| Dependencies refreshed.
| Compiling 143 source files
| Compiling 143 source files.
| Error Compilation error: startup failed:
C:\Users\my-id.grails\2.0.4\plugins\export-1.6\src\groovy\de\andreasschmitt\export\builder\ExcelBuilder.groovy: 5: unable to resolve class jxl.format.Border
# line 5, column 1.
import jxl.format.Border
^
C:\Users\my-id.grails\2.0.4\plugins\export-1.6\src\groovy\de\andreasschmitt\export\builder\ExcelBuilder.groovy: 26: unable to resolve class jxl.write.WritableFont
# line 26, column 1.
import jxl.write.WritableFont
^
I don't know if this is particular to this export plugin or all of my plugins.
Any idea what would be the issue? Thanks in advance for your help.
Grillo9