Weird Probs....PSU Related?

Hello, well basically, im using the 340/350w cheiftec PSU that came with my cheiftec dragon. Just added a DVD-R but these problems did occur BEFORE i installed it. Sometimes, when i switch off my pc, it will reboot instead of turn off. :confused: Also, used the DVD-R for the first time today, and it failed. The error was power related. Just as a note, the PSU is running the following-

3 hdd's
4 case fans
a CD-R, a DVD-R and a floppy drive
2 x Cathodes

(Things that do not need a molex connector)
GF FX5200
SB Live 5.1
2x512ram
P4 (not overclocked)

I've had a look on Asus PC Probe, and the power supply SEEMS to be giving enough juice, currently the 3.3 is at 3.408, 5 is at 5.214, and the 12 is at 12.159. If im a complete n00b and theres something up with them figures, tell me. Also, if its the PSU that dodgey, could you recommend another? Needs to be over 480w due to the fact i soon will have deep pockets and going to go for one of the newer GPUs. Thanks in advance

Try unplugging everything that's draining power that you don't need e.g. optical drives, PCI cards, and see if the problems persist.

strange that may be my prob, i have a dragron dx01, they prob i get is with bootup after loading screen... goes blank . so have to restart serval times.maybe the 360psu