If you search for my username, you will note I had installation problems of ZenPhoto 1.2.6 on my ISP, which is ReadyHosting, using Windows 20003 Server, IIS and MySql. I could not find a proper installation guide and while there has been no developer testing on a Windows environment, some people here have done it but in general there is no concentrated guide.
Well as it turns my problem was not that complicated. All I had to do was make sure the mbstring extension was turned on which it wasn't before. This fixed my problem and all is well.
I will say that while I love this package, it does run somewhat slow even after I cached all the images. Hopefully as I learn more about how this works, I can tweak it to run better.