I am getting this error when I try to post new images to my blog.

These images are panoramic images created with an automatic stitching utility callled "PhotoStitch" - which was came with my Canon EOS 40D. The output of this app was saved as both TIFF and JPEG, but both gave me the above error. I have tried different images - but they all give the same error.

Other panoramic images, created with my iphone 3GS and the app "AutoStich" work fine when I transfer them to my mac and upload them to my blog from there. (but the panoramic images aren't uploaded to my blog when I email them from my iphone to: TimPearceCanada.pfgsu@photoblog.com)

Thank you for any tips.
Tim

EDIT:

I am now getting the error: XXX: .tif when I try to upload .tif files to my blog. These .tif files are not panoramic, and are single images. I scanned the negatives and, after editing them in PhotoShop, output them to .tif format.

EDIT 2:

I've been able to attach .jpg files to my blog, but not .tif. Does this site not work with .tif files?