Somehow, that problem tickles a brain cell, but I can't find any information about it, or remember what it was all about.
What version of OS/2 or eCS are you using?
What version of JFS are you using?
What parameters are you using on the IFS lines in CONFIG.SYS?
What kernel are you using?
Exactly what drives, and format, are you using (all of them)?
Have you got
DLLBASING=OFF
near the top of your CONFIG.SYS?
Do you have
EARLYMEMINIT=TRUE
near the top of your CONFIG.SYS?
Many years ago, there was a JFS update that required you to reformat any JFS drives that you had, to actually fix a problem that the JFS update fixed (but I don't think this was one of the symptoms).
Hopefully, something will trigger a memory recall, or give you something to try.