I've had my 5005 for two years now and with the original drive (DDW 451S) I never had much luck with dash media. For my 5005, using a low speed (1-4x) +r or +rw has always worked. These days I almost exclusively use HP branded PHILIPS 041 +RW to record anything and then do the editing etc. on the computer.
Around the beginning of this year I replaced the drive and dropped in a LiteOn 160P6S and the recordings only got better and more reliable (but I still don't trust dash media).
Hope this is somewhat helpful.