As header says I can no longer right click to select. But I can select with Ctrl-right_click. To select multiple objects I must Shift-Ctrl-right_click. This is case in 2.49 as well as 2.50.
Not sure if this is relevant at all. But this behavior appeared after upgrade to Karmic Koala and latest radeonhd drivers and kernel 2.6.32-rc4.
Edit: Also I can not use 3d-handles to move/rotate/resize, but hot-keys work.