FileCore MiscOp 1 Changed issue

I think a bug was introduced in the handling of floppy disc changes notified via MiscOp 1 in RISCOS 3.6.

Up to and including RISC OS 3.5, replying to MiscOp 1 with Changed when a floppy change is detected and subsequently replying with No Change, is sufficient for a floppy change to be detected by the OS. From RISCOS 3.6 onward, changes are only detected if Maybe changed is returned at every MiscOp 1.

Detailed documentation is lacking on this call, but I believe the way it should work is:

IF sequence number has changed THEN
Update internal sequence number with the number passed by FileCore in R1
Exit with Changed works and Maybe changed set in R3
ENDIF

IF floppy has changed since last called THEN
Exit with Changed works and Changed set in R3
ENDIF

Exit with Changed works and No change set in R3