Hi Frank, I am indeed maintaining a Windows version of AOLserver, though at the moment I only have HEAD built (4.1), and not 4.0.8. I did try native Win32 PostgreSQL back when it was still PostgreSQL 7.5 beta. It seemed to be running smoothly, but I did see the same 7.4 -> 7.5 problems in OpenACS that you see and that Jeff has committed patches for. (I haven't tried an install with Jeff's patches.)
I put a zip of recent AOLserver binaries up at http://www.jamierasmussen.com/download/
AOLserver 4.1 is still Alpha, when 4.1 final is released I'm hoping to rebuild the installer and host it on SourceForge. The installer by Vlassis uses PostgreSQL on Cygwin and some fairly recent binaries from me. The native PostgreSQL installer is quite nice. My personal preference would be to have separate (but simple, GUI-based) installers for the database, web server, and OpenACS / dotLRN, since I think maintaining a combined installer will be more difficult. Vlassis' installer does have some nice features, but requires downloading a whole Java distribution, etc.