Rebooted?
Repaired Permissions in Disk Utility?
ZAP'd the PRAM.? (Hold down Command + Option + P + R keys immediately after the first chime and hold down until the third chime)
Created another Admin account and logged into it?
P
Mac 10.6.8 (snow leopard?) . Sudden appearance and can't open any applications. Using Firefox but it happened with Chrome as well. What is this and how can I fix it?

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