Command-Delete deletes a line, but how do I undo that? (CMD-Z doesn't work)

[LTX]

I find myself erroneously hitting Command-Delete instead of Option-Delete occasionally (like in these forums), which deletes a line of text, but I don't seem to be able to undo that action. Undo doesn't work, Redo doesn't work. Is there a way to undo the deletion?

Thanks.

P.S. okay, now it's working intermittently. I can CMD-Del the "Thanks." line and CMD-Z to get it back, but when I type "P.S." and CMD-Del it, CMD-Z just backspaces up to the end of the Thanks line.

 

[LTX]

Nobody knows?