Image resize fails on IIS 6.0

Hello all,

I'm a relative beginner in Drupal but well-versed in programming, helping set up a drupal site.

Using ImageCache I've added a simple image field to the Blog content type. It lets bloggers upload images and resizes all of them to fit the window width. On the local development machine the image field works, but we've discovered it does not work on the server. When attempting to upload the image, Drupal creates a thumbnail, successfully saving the fully sized image on the server. However, the resize seems never to take place.

The main difference between local installation and the server is that we're running apache2 on a Mac locally, and the server has IIS 6.0 on a Windows box. We've made sure with the server tech people that all the directories under sites/default/files are writable, and we also configured temporary directory appropriately under admin/settings/file-system. However, the image upload still does not work.

Please advise.

Many thanks,
Zoe & Miran