Apple Mac 9600/350 problems

Hi,

Im having trouble with my 9600/350. It used to run fine, but Ive since upgraded a few things to put it to work in my audio and midi studio. It has an opcode studio 4 on the printer port, an m-audio audiophile 2496 pci card and 2x2 usb midi box, a usb 1.1 card, a 6mb pci mac video card, a digidesign sample cell pci card, a 9gb scsi HD and a scsi CDROM and ZIP drive as well as 500mb of ram running on os 9.1 with OMS installed as well as the relevant drivers for the other audio gear. The machine seems to crash randomly, and especially when trying to play back or record in logic or cubase via the 2496 card. Can anyone offer any suggestions please?

Thanks,

John