This is because Powerpoint format materials posted by instructors are best accessed for me with Safari on a Mac; Acrobat materials best accessed by IE in the Windows environment, etc. (I installed Bootcamp software, then Windows 7, to be able to do this; the three browsers I turn to are Safari, Firefox, and IE).
I have gone out of my way, with the above, to access all materials that wouldn't be accessible across the board without these means..
However, when I am in the Mac OS X part of my laptop, failing to download something using Safari, and turning immediately to Firefox, occasions a "Guest Login" prompt, and denies me access, assuming I am a different user who has broken into my own account.
Working with different browsers, and even 2 different environments/operating systems on the same machine, is fine-- it took me awhile, but I have made my machine capable of accessing all materials instructors post.
But it is onerous to have to be re-validated as a user every time (after being denied access to Moodle) because I must switch the methods I use.
Perhaps someone could greenlight my account, or recommend some other means for me. I use several means to access course materials because they are posted in a variety of formats, and I use a Mac. Any suggestions or permissions given my account would be valuable.