Error when uploading Box Image

[shaunareid 1]

I was editing a Box today and wanted to upload a different image for it.When I clicked Upload I got a message: "Upload Error: File is empty. Please upload something more substantial." I tried uploading a totally different image but got the same message. I've tried both JPG and GIF. I also tried creating a new box, rather than editing an existing one, but same error. Next I tried adding an image via the Media section ("Upload New Media") and got the same message - I tried uploading a variety of images there too. I also tried it with both Firefox and IE (on a PC). Has anyone experienced this or possibly know what is wrong?

[Kate 3]

Hi Shawna - If you're experiencing it via the "Upload New Media", then it sounds like a WP issue as opposed to a theme issue. Are you running the latest version of WordPress?

[shaunareid 1]

Hi Kate, Yep I'm using WordPress 3.0.4. and the latest version of PageLines - upgraded both a week or so ago. Uploads were were working fine til today so very strange. Will get in touch with my developer...