Thread:Project:Support desk/Error creating thumbnail

I am getting the error message in the subject whenever I upload some image files (the only kind I have tried to upload so far). At the end of the upload, instead of seeing a thumbnail of the image, I get the message, "Error creating thumbnail". It almost seems like the size of the images might be the factor, but I don't know if this is true or not. For example, I uploaded a file of size 466 × 696 pixels, file size: 46 KB, and got the error. But when I uploaded a smaller version of it, 200 × 299 pixels, file size: 41 KB, the error didn't occur. The difference in file size seems negligible, although the pixel dimensions are more so.

I tried to upload successively larger pixel-size versions of the image, and did not get "Error creating thumbnail" until I tried 450x672. The next smaller size that didn't toss the error was 400x597. Incidentally, the file size on the 400x597 version was 100KB, twice as large as the original image that tossed the error.

I am using:
 * MediaWiki 1.19.2
 * PHP 5.3.27 (cgi-fcgi)
 * MySQL 5.1.56-log

My wiki can be found HERE, and a specific example of the problem is HERE.