[radeonhd] Screen doesn't rotate

Hi, I have a Radeon HD 2400 PRO, with radeonhd driver 1.2.4, xrandr 1.2.3 on a Ubuntu Intrepid with ubuntu kernel 2.6.27-11-generic x86_64. I am not able to rotate screen:

xrandr -o 1 X Error of failed request: BadMatch (invalid parameter attributes) Major opcode of failed request: 152 (RANDR) Minor opcode of failed request: 2 (RRSetScreenConfig) Serial number of failed request: 12 Current serial number in output stream: 12

I attach you configuration and log files. Thank you. Best regards, Emiliano Rago -- "Un uomo sano di mente è uno che tiene sotto chiave il pazzo interiore" - Paul Valéry