In case you haven't found an answer for your problem do the following:
The FAQ can be found here.
The user mailing list is here here. Please state in the subject to which dirver if it's related (i.e. "radeonfb:").
To view previous bug reports or file a new report, click here.
To contribute a patch or view others patches, click here.
In case none of the above satisfy you, mail to Otto Wyss but I can't guarantee you get a useful answer. Keep in mind this software is provided as is.