Did the harddrive crash while using Samplitude 5.5 ?
Do you mean it doesn't playback at all, or just while you're recording? It may have something to do with your ASIO driver if only the playback during recording is harmed.
Otherwise it might be a codec problem, so I'd need to know which files you try to play.
Try pressing "Y" (I hope it's Y back at 5.5...I use Samplitude 11) and check the settings of recording, especially the latency model.