IBM PS/2 memory

Just dug my IBM 65sx out, which had already lost 2 of its original 6MB due to a bad memory module - but it seems like the remaining 4MB is not very happy, either, and it flakes out at 3.7MB or so. Obviously I need to source some replacement RAM. Does anyone know if the systems are picky about what they'll work with? I believe they have to have parity (unless there's some magic jumper/setting somewhere to make it work with non-parity stuff), but are there any other gotchas involved in terms of DRAM type, capacities etc.? (I'm wondering about trying some of the RAM from my SGI Indigo2, but I think that would mean losing 128MB from the system to give up a 32MB module for the IBM, as I believe the SGI needs them to be installed in groups of 4 - that's assuming that it's even compatible, anyway) cheers Jules