Beaming in r.1321

There seems to be some problem with the beaming in r.1321.

Have a section with beamed quavers and semiquavers.
Change time signature to 5/4 - beams are grouped in 3+2
Undo
Beaming changes aren't undone.

I also note that if you click on the (new?) .. button, and then undo, again the beaming isn't undone.