Here's a weird one:
I booted up my OS4.1FE partition on my 4000T to discover that all of my SFS partitions (the drive has around 7 SFS partitions and 1 FFS Intl) were set to read-only, including the OS4 partition itself. Admittedly, it's been a while since I booted OS4 on this machine but I'm pretty sure SFS was operating normally the last time I did. I don't think I've changed anything in hardware or software since then. SFS 1.279 (68K) is in the RDB. The partitions all work correctly (read/write) when I boot into OS3.9. The only way I was able to get the OS4 partition usable from OS4 again was to reformat it as FFS DOS\07 and reinstall.
Any ideas as to what might have happened?
If it worked under OS3.9 then perhaps your problem was OS4 and the re-install fixed that. After re-installing OS4 with FFS could you then read the remaining SFS partitions?