I was able to fix the collapsing forum issue by modifying the parse_templates plugin. I found the problem was related to missing </ol> tags in the html code delivered to the browser by comparing output using the baseline configuration where the collapse feature works, and with the Sub-Forum List Control enabled.
I tried to locate where these tags were supposed to be reinserted into the content per the embedded notes but I never determine where that should have been.
In the parse_templates plugin:
Replace:
PHP Code:
$vbulletin->templatecache[forumhome_forumbit_level1_nopost] = str_replace($Sorky01_SubforumOLBefore , '', $vbulletin->templatecache[forumhome_forumbit_level1_nopost]);
With:
PHP Code:
// hack to fix collapsing forums
// $vbulletin->templatecache[forumhome_forumbit_level1_nopost] = str_replace($Sorky01_SubforumOLBefore , '', $vbulletin->templatecache[forumhome_forumbit_level1_nopost]);
// end hack