BuddyPress.org

I comment the lines in the .htacces out and hacked the bp-core-avatar.php as mentioned.

I would restore these files back to their original coding before you continue looking into the cause of this particular issue. The advice from that particular member was from 5 months ago. Since then, many bug fixes and improvements have been made in BP.

When it comes to the BuddyPress core files, it is never a good idea to hack them. Do not touch to core files. We will not be able to help you if you are not using the same core files everyone else is using.

Once you have done that, answer these questions:

1. You’re positive that the permissions on blogs.dir and the existing subfolders are set to 777?
2. Are you uploading a gif or png image?
3. Are there ANY errors in your log file? If so, what are they?
4. You mentioned that this issue occurs no matter what browser you try. Which versions of Firefox and Internet Explorer are you using?