[linux-audio-user] Device for simple stereo dubbing?

Stepping gingerly back into the pond... I have a desktop Mandrake 9.1 system, on which I'd like to do rather simple audio stuff (nothing particularly audiophile or performance-oriented for now). It has an onboard soundcard which plays sufficiently well, but records quite badly, with most things that I record from cassettes and the occasionaly DAT distorting quite badly. I have a Roland UA-30 USB Audio device, but so far I've found that plugging it in when the system is running crashes the machine completely, and that the machine fails to finish booting when I boot it up with the device already hooked in. Is it worthwhile getting another soundcard? Would something as simple and inexpensive as a Soundblaster 16 PCI be sufficient? I'm not all that sure what software I have running at the deep level, since I've installed enough stuff that has pulled in other things via dependency catching in urpmi that I'm not clear, for example, on whether I'm using ALSA or not. For the user-end apps, I've been using Audacity and Gnusound to record and edit and XMMS for most playback.