This is actually 0.9.21 as it's the CVS version. Linux Ubuntu Intrepid RC.
I don't have a printer set up. I tried to print to see what happened (and to see if it told me it had saved the painting like the bug I've just forwarded).
Tuxpaint told me it had printed. The command line has the following error:
lpr: Error - no default destination available.
We should look out for lpr errors and flag them up.