I was having an issue with uploading issues Windows but you might want to check out http://epirsch.blogspot.com/2008/01/fixing-attachmentfu-on-windows-like.html
Mark,
I had the same issue with 'Size' and I tried the patch from the url that you posted. It works fine. But if i try to upload a file with .JPG (note the uppercase extension), i still get an error "Content type is not included in the list". I tried including the extension in the plugin but still did not work.
Is there any work around to fix this.
Thanks