Problem Uploading Plugin

When attempting to upload our new plugin at http://wordpress.org/extend/plugins/add/ I contiually get the following error:

That name already exists. Please choose another name.

I have tried different names (it certainly doesn’t already exist) and tried changing the description and even the link to the zip file. I read on another post that the problem can the length of the inout fields but again I have checked these and am within the limits.

Can anyone suggest what the problem might be please?

Thanks