symptom: when starting openoffice.org, the program loads, the main window comes up, and XWindows freezes. The mouse still moves, but no input is received and any moving graphical elements like stripcharts or xmms title freeze.
Explanation: you have an nvidia card, and have enabled XRENDER acceleration. When OO.o tries to do its internal font smoothing, something screws up in the acceleration.
Soltution: Experimental video acceleration options, how naughty! Turn off XRENDER acceleration, or disable font smoothing in OO.o somehow.