I used evtest tool to check what does the 'input' see, it looks like it sees that keys are being pressed:

Event: time 1258985728.318237, type 4 (Misc), code 4 (ScanCode), value 70013
Event: time 1258985728.322357, type 1 (Key), code 25 (P), value 1
Event: time 1258985728.351623, -------------- Report Sync ------------
Event: time 1258985728.366607, type 4 (Misc), code 4 (ScanCode), value 70013
Event: time 1258985728.367553, type 1 (Key), code 25 (P), value 0
Event: time 1258985728.369964, -------------- Report Sync ------------

Nokia-N900-42-11:/dev/input# /debian/usr/bin/evtest /dev/input/event4
Input driver version is 1.0.0
Input device ID: bus 0x5 vendor 0xa5c product 0xcdef version 0x300
Input device name: "Think Outside Keyboard"

Event: time 1258985734.619110, type 4 (Misc), code 4 (ScanCode), value 7002d
Event: time 1258985734.623657, type 1 (Key), code 12 (Minus), value 1
Event: time 1258985734.628509, -------------- Report Sync ------------
Event: time 1258985734.692718, type 4 (Misc), code 4 (ScanCode), value 7002d
Event: time 1258985734.695312, type 1 (Key), code 12 (Minus), value 0
Event: time 1258985734.700714, -------------- Report Sync ------------

'p' key above work. The '-' (minus) key doesn't work for me, but evtest sees it.
Maybe there is an issue further down the stream ?