Quoting ArcosCom Linux User linux@arcoscom.com: *snip*
Checking maximum texture size : failed
Root window size (2960/1050) is bigger then maximum texture size (2048x2048)
Are you trying to span your display across the laptops LCD and the external one? If so, does your final total resolution happen to be 2960x1050?
It looks like that's where the issue is, however I haven't played with beryl in quite some time now...