few thoughts --
1) do you have (or can you find/borrow) an cd/dvd player with a digital output (preferably coax AND optical) -- I'd start by seeing if you can narrow down the root cause -- dvds are generally 48k, so you should be able to test the same scenario (48k digital in) using a dvd in a dvd player -- cds are 44.1k -- If the cd/dvd records fine using the same cable/coax input, you've confirmed that your dap1 is your problem -- if you run into the same issue with the cd/dvd using coax, you could run the same tests using the card's optical input to further narrow down the problem (is it a driver issue or a hardware issue -- both inputs causing the same problem could be driver-related, only one input having problems could suggest hardware.
2) if the above results in the same problem on all tests, I'd a) confirm that you're using the best/most current/etc. driver, and if a driver update doesn't help, b) try moving the card to a different slot -- sometimes, physical card location can cause a problem too . . .
hope this gets you somewhere!