Mime type for gif is: image/gif
Mime type for jpeg is: image/jpeg
I cannot view both gif and jpg in my phone. If I send the image via MMS, it prompt me: "Unable to open file". Other image file I sent via MMS, is OK. Only this 3 got problem.
If I download the file via WAP, it says, file received, then when I do a option->view, it says: "memory not enough". I save the image into Gallery, and try to view from Gallery, it still say "memory not enough" (i can open other images).
Same kind of problems I have with Nokia 6100 when I tried to your pictures. Here are solution, which helped me:
There was transparent values in picture. I converted GIF-file to TIFF (which doesn't support transparency) and then back to GIF-file and now it works and doesn't give odd error messages anymore :-)
File was greyscale and with some color palette, which I haven't seen before. I transferred picture to colourpicture (RGB-palette). Now it is a little bigger, but after conversion, it is visible in phone.
There was transparent values in picture. I converted GIF-file to TIFF (which doesn't support transparency) and then back to GIF-file and now it works, like other GIF-file.
I hope these instructions and tests will help you,