I'm working on a file upload utility based on Valum's Ajax-Uploader. The idea is similar to the Gmail attachment process. The user should be able to drag a file from the desktop into the browser window and onto the file upload area to get it to upload. This works fine in the browsers that support this functionality (Firefox 3.6+, Chrome 7+).

The problem I'm running into are the styles that should be re-drawn when the user:

1. Drags the file anywhere in the browser
2. Drags the file into the upload area

I have tested in the exact same browser versions on WinXP, Vista, and Win7. The appropriate styles are redrawn. However, in Windows Server 2003, they do not.

In Win2003, when I inspect the div that should be redrawn via Firebug, the "drop-area" and "drop-area-active" classes are applied correctly. Firebug even shows the correct style declarations, but the changes are never visible.

The only difference between FF and Chrome that I'm able to spot is that in Chrome, the "drop-area-active" style is displayed for a split second when the user drops the file.

I'm not positive that it is a Windows2003 issue, but that's the only OS in which I'm able to recreate the bug.