Issue: Login via pda skin (add /portal/pda to your URL) and go to Resources for a course site. When you try to upload a file, "Browse..." is greyed out. If instead of clicking Cancel you click "Upload Files Now" it will reload the screen with the error message "Alert: The upload size limit of 40 MB has been exceeded."
A long term fix would be to allow you to use the Choose File button, but it's not clear whether that is a fix we can make without changing the method of browsing--it appears the iPhone browser may not support this. (Not sure if iPhone4 has same issue)
In the meantime, the error message should be more accurate. It should say something like "Alert: No file was selected. Choose a file or click Cancel" (currently on non-mobile interface, you go back to the Materials file tree if you haven't selected a file when you click "Upload Files Now"--this is also acceptable, but not ideal; in that situation, the suggested Alert would also be appropriate).