Hi Dan, I went that path also (dist-upgrade to get potato) and had some of the same problems.
The most serious for me was that my pcmcia modem card stopped working somewhere along the way. After recompiling kernels and pcmcia and different options etc I gave up. I reinstalled (slink) from scratch and have proceeded step-by-step in moving to potato. Compiling the kernel-source-2.2.13 and pcmcia-modules-2.2.13 (and versions 2.2.12) from potato results in a non-functioning pcmcia. Previoulsy I compiled the kernel/pcmcia sources (2.2.12) from slink (under slink) with no problem. I have yet to see if I were to grab the kernel/pcmcia sources from slink whether it makes any difference. I trust someone can shed some light on this? Cheers, Graham