help! can't record in 2.5.1!!!

Loaded.
Selected "new"
Ran through the screen: Blank unknown instrument (yes, I'm lazy)
4/4, key C, blank name.
Adjusted tempo to 100 or so.
Checked metronome.
Pressed red button.
Message "command is unexpectedly complex" and no recording although cursor is moving and clicks are clicking.
All midi settings are as normal.

I've shifted back to 2.4.1 'cos I didn't have a backup of 2.5 which was working fine for me.