10.0.4 Dock Problem


Hi Guys/Gals

I have a problem!!!! my iBook 500 ( CD-ROM, 320 MB ) is playing up!!!! for some reason, when using Mac OS X 10.0.4 sometimes when i launch an app, it launches fine but the icon does not show in the dock! this seems to happen alot with Mail, but has been known to happen alot with ICQ, but otherwise it is totally random, it has happened to system prefs, terminal, netinfo, pretty much everything. Also, sometimes when i close an app ( Classic or Native ) the icon stays in the dock with the triangel below it, even tho the app is fully closed, it wont let me drag the icon out of the dock....????? does anybody have any ideas???? By the way i think the "Device" is gonna be some sort of digital radio like the Psion Wavefinder
Cheers ppl