Audio delay with Creative Audigy Soundcard

[atoal]

I have my ps3 hooked up to my computer's creative audigy 2 zs soundcard with an optical cable. after a while the sound starts to lag and delays. it has done this on more then one device. it did it on my ps2 and on a dvd player, both were using digital connections. if i unplug the cable and plug it back the delay is gone. i know someone else who has experienced this same problem with a digital cable box when using the optical input. i have the newest drivers installed for the soundcard and i have tried it with an older driver and that doesnt solve the problem

anyone know of a reason for this or a possible solution?

here are my computer specs:
Motherboard: ASUS A7N8X-E

Processor: AMD Athlon XP 2400+

RAM:Crucial 512MB 184-Pin DDR SDRAM, CORSAIR ValueSelect 512MB 184-Pin DDR SDRAM, CORSAIR ValueSelect 1GB 184-Pin DDR SDRAM

Soundcard: Creative Audigy 2 ZS Platinum

Speakers: Creative GigaWorks S700 5.1