Had almost the same problem after an update from gutsy to hardy, used URandR dualscreen setup on gutsy:
Option "MigrationHeuristic" "greedy"
AND
Option "DRI" "false" # Was set true on gutsy
Prevents from crashing with a virtual of 2960x1050
Had almost the same problem after an update from gutsy to hardy, used URandR dualscreen setup on gutsy:
Option "MigrationHeuri stic" "greedy"
AND
Option "DRI" "false" # Was set true on gutsy
Prevents from crashing with a virtual of 2960x1050