Did some sloothin' & came up with this thread by jeff from yesterday @ sonic sense. Seems that he was just setting the recording device to ASIO & the actual file to 24/48 but not changing the actual ASIO settings from 16/48 to 24/48. Causing the MME to send a dithered. So as long as the bit meter says your files are 24bit you should be all good recording via wavelab. Also sounds like he is having the same problem i had now. Constant clipping on the meters. Which could probably be fixed via a USB 2.0 PCMCIA card.
Ok I have been very careful to set the asio settings to 24 bit using the mme. I guess it's all good then. Thanks for the digging.