ASP - file Upload

I inherited a site which was created in ASP.

The file upload feature has worked in the past but has stopped working.

When you upload a file via the 'Browse Server' - you can choose the file and then the box just sits there with the message:

'Upload a new file in this folder (Upload in progress, please wait...)'

The file does not upload and the status bar in the browser 'loads' like normal for about 2 seconds and then stops (it is a small file I am testing with).

I have checked the config files and both have the ConfigIsEnabled = True set properly.

Any suggestions on what I can do to figure out what he issue is?