First off, great work. Your AD functions are fantastic.
I have a bug/issue to report:
I noticed when I installed version 3.3.4.0 of AutoIt the _AD_IsMemberOf() function no longer works (i was using ad.au3 v0.33). It simply returns a -1. I rolled back to 3.3.0.0 and everything works fine. However, other functions such as _AD_GetUserGroups work with the new version. I also tried the original adfunctions.au3 file, and it also returns -1.