It needs to be in 44.1 because CD-Wave only cuts at multiples of 588 samples. 588 samples is 1/75 only at 44.1khz. At 48kHz, it either won't put the track markers in the right place, or it'll resample and then place the track markers (not sure what it'll do because I've never done it). So resample (preferably in another program, it sounds like), then split with CD-Wave.