[Typo3-windows] IIS permissions issues

[John Nicholas]

I usually run typo3 under apache on linux but have a client running it 
under IIS using Zend WinEnabler. (This is fastCGI style approach that 
also includes Zend Optimizer) Most of the system runs ok but I have a 
couple of odd problems.

First, I cannot edit text files in Fileadmin, I just get a 500 error. 
I'm not sure where to even start chasing this down.

Second, when I upload images in fileadmin there is something subtly 
wrong with the permissions so that imagemagick cannot manipulate them. 
If they are not being resized or anything they serve fine but if they 
get resized the don't work and thumbnails don't work. I can log on to 
the server and do an "inherit permissions" update and everything works 
fine but it does prevent my users from seamlessly using the backend.

Thanks
John