The 48x speed is for write once discs, for RWs your drive must have another speed (32x, 24x or 16x).
With all the problems associated to packet writting software, if you want to use RWs as such you have to use it (InCD, Drag to Disc, DLA, for instance).
If you only use XP to burn the discs you are using them as CD-Rs.
IF you write to them at different times (more than once), XP may become confused and I don't know if it can add data to a disc already used before. But even if it does, at the end it will be difficult that XP can read the later sessions.
Using RWs with XP, requires you ask the O/S to delete (clean) it before any new use.
All together, it can be a reason why your machine gets frozen, but just a guess.
I did use Memorex discs with no problem (either CD-R and CD-RWs), but it may happen your machine doesn't "like" them.