monitor resolution too high
improperly oriented keyboard
network packets travelling uphill (use a carrier pigeon)
Decreasing electron flux
first Saturday after first full moon in Winter
radiosity depletion
CPU radiator broken
It works the way the Wang did, what's the problem
positron router malfunction
cellular telephone interference
techtonic stress
piezo-electric interference
(l)user error
working as designed
dynamic software linking table corrupted
heavy gravity fluctuation, move computer to floor rapidly
secretary plugged hairdryer into UPS
terrorist activities
not enough memory, go get system upgrade