Thank you both for attempting to duplicate it. I guess this is specific to my setup
The basic outline of which is listed below for reference. I tested with all the other extensions/plugins enabled and also tested with all the other extensions/plugins (besides Adblock Plus and Better Privacy) disabled. I don't know if that is functionally equivalent to not having them installed, and there there are the various Firefox option adjustments I made. If I find some time I may try to dig into this further. For right now though I think I'll just run with filter hit counting disabled.
Windows XP SP3 (x86, fully patched)
Adblock Plus 2.1.2 (EasyPrivacy+EasyList, Antisocial, Malware Domains)
All-in-One Gestures 0.22.1
Context Search 0.4.6
Adobe Acrobat 10.1.4.38
Shockwave Flash 11.3.300.271