Delta 66 and crackle/sizzle Producer 8.5.X

Hi and HELP!

Recording and playing audio I get a sizzling sound. WDM or ASIO makes no difference. I don't get it in Sound Forge.

Config:
Windows 7 32 bit
latest M-Audio Driver (5.10.0.5074)
P5 750
Intel DH55HCMB
Sonar 8.5.3
ATI RADEON 24HD Video Card

No IRQ conflicts
Tried all 3 PCI slots
disabled all other devices except video and SATA (obviously)
tried asio4all
changed buffer settings to ridiculous proportions
disabled the D66 devices in the Windows Control Panel

If I don't get the sizzle recording, it will show up in playback/mix down. Audio exports with it as well.

I'm at my wit's end - open to all suggestions including recommendations for a decent replacement, I really don't need all the power of the Delta 66, and definitely not all this frustration.

Thanks!!!

Tom