I just made 1.3.23 available, as 1.3.22 had a few problems that made it more-or-less unusable for some people. I hope 1.3.23 fixes the bootup panic with the SLIP driver. It should also be better at recognizing harddisk partitions, but maybe the numbering changed a bit.
If you have problems mounting some of your partitions, could you please check the bootup messages about the partitioning? It should look something like this:
Partition check: hda: xxx hdb: xxx
and I'd be interested to hear about differences in output between 1.3.23 and earlier kernels..