Uploading Media Errors

I have a folder with 26 pics on my desktop. When I go to upload them all, the 1st 3 will upload & then the rest wont and I get an “http error”. I use safari then switched to firefox and same issue. I also upgraded to WP 3.5 thinking maybe that was it but to no avail. Its frustrating that I can do everything except upload new media. Any idea whats causing these so called time out errors? Thanks