Running PHP under IIS is really annoying.
That is all.
Update: OK, it was actually a problem with importing Cacti's default SQL schema into MySQL that was causing PHP to barf, not PHP or IIS themselves. Now I'm getting my hate on for Windows SNMP. Grr.
Update2: Screw this, it'll be faster to setup a *NIX box and the apps than trying to get the apps working on Windows