[TxMt] progress.rb question about Cancel button

[Hans-Jörg Bibiko]

Hi,

I have a problem. I took the finite example coming from progress.rb to  
figure out how to cancel the block running inside of  
TextMate.call_with_progress.

If I have a TM Ruby doc with the code and press apple+R the Cancel  
button works. If I have the same code in a tmCommand the Cancel button  
does not work, even if I store the code as Ruby file somewhere.

Is this something which should be fixed in the future?
Is this my fault? If yes, how is the correct syntax or workaround?

Thanks in advanced,

--Hans