I am using mybb and recently i have been facing problem uploading avatar and themes... or i should say installing with xml file ... mybb discussion board says there is some problem with the php server ...
one more thing please do not tell me to chmod my upload directory to 777 coz i have tried that thing .. .. i would highly appreciate the administrator to come out with a solution

Provide an error then......

Please correct the following errors before continuing:
The file upload failed. Please choose a valid file and try again.

this is the error mybb shows me .. the file i upload is well under the dimension and size protocol
I tried every dam format of the file i.e. jpeg, gif, png even bmp but my every try goes in vain ....There was no such upload error while i was using phpbb