Upload Problems

When I try to upload images in the my account -> edit menu, I seem to get the following error displayed on the top of the contents column:

* File copy failed: source file does not exist.
* Failed to upload the picture image; the pictures/ directory doesn't exist.

And in the admin error log I will see:

* For /tmp/phpLhHQuw the system thinks its MIME type is application/octet-stream while the user has given image/pjpeg for MIME type
* For /tmp/phpLhHQuw the system thinks its MIME type is text/plain while the user has given image/pjpeg for MIME type

However, I can take the same file and convert it from JPG to GIF, and it uploads fine. But not all GIF files will upload OK, some of them produce the above mentioned errors.

Also, when I try to do an attached with a BLOG entry, I see similar errors in the error log if I'm uploading an image file, but the system does not complain to the user. A text file seems to upload OK with no user or log errors, but the attached file is no where to be found on the system once its uploaded. I've set uploads to "public" and I have a files/pictures directory, both being world writeable (is that safe?).

This seems like it is a apache or PHP configuration issue, no?

Thanks for any guidance you can give me.

Regards,
Kory