We've got a couple of websites which are hosted by other companies, but a content management system is provided for users to edit pages.
With Windows 7 rollout we've found that the uploading of images seems to work but times out. The image can be selected as usual but when you click to upload it says waiting for server.com until finally timing out.
It's hard to research - I've got as far as discovering that Windows 7 SP1 works fine but some post-SP1 update seems to introduce the problem.
It is not browser-related, it happens in any browser.
Tim Gowen