[OS X TeX] Possible TeXShop bug in saving when file is already open

[Luis Sequeira]

I like to use the default "Untitled-n" file name for quick tests of things like example code I receive, and that I will probably delete soon after. 
Today I got one such example from the pstricks list, opened a new file - which TeXShop name Unititled-2 - pasted the example code and tried to save.

I got the usual dialog indicating that such file already existed and hit "Replace". It turns out that another Untitled-2 was still open from a previous example.
This caused TeXShop to give the spinning wheel and eventually I had to force-quit.

Wondering if it had been a one-off event, I deliberately caused the same situation, and again got the wheel.

I think the expected behavior is to warn that it cannot save - certainly it should not give me the spinning wheel...

What gives?

Luis Sequeira