So, I have a strange issue with Drupal imagecache.
When I upload an image, the image is correctly stored in a folder, but imagecache doesn't generate the other cached images.
thanks
Check out Imagecache's troubleshooting guide in the handbooks. In particular, check the logs for errors explaining where the process is breaking down.
Also, check the paths that are included in your pages and make sure they are still correct, now that you've moved the site to a production server. This issue has some more tips, specific to the path problem.
Finally, if none of that helps, check the issue queue. There are several issues related to IIS.