Reaper crossfades won't work

[floid]

I've been doing edits in Reaper for years by just lining up two clips where I want them and then dragging the top and tail until they overlap each other. Reaper has always automatically put a crossfade on the overlap, and I can usually eyeball it and get where I want to be fairly quickly.
But today the automatic crossfade feature quit working, and I can't figure out why. Maybe some errant mouse click? What should have been a quick comp/edit has slowed to a crawl.
Any ideas?

[sound for sandwiches]

I got nothing, but last night I couldn't get the "cursor to edge of item" command (control+[, control+]) to work, would just get the mac error beep. frustrating...

What does happen in the overlap?

[sound for sandwiches]

The Reaper shortcut list says "toggle auto crossfading" is Alt+X. Try that?

[floid]

Alt+X must be it. I use Alt+Z (cut at previous zero crossing) quite a bit, must have toggled it by accident.
Thanks!
Was having an awful time getting some of the tight fades to sound right - tweak length, tweak overlap, tweak fade, listen and hear glitchiness where the fades didn't perfectly line up, tweak again... i hobbled along and powered through but it was a miserable couple of hours.