Warning: Objects of graphics.plotmanager class exist - not clearing this class or any of its super-classes

Hi,

I've been getting this error recently, and I've tracked it down to this line of code:

annotation('textbox','String','testing');

After closing the figure that appeared, I entered:

clear classes

And then I get the following error:

Warning: Objects of graphics.plotmanager class exist - not clearing this class or any of its super-classes

Can anyone reproduce the same error?

Regards, Yu Ang

PS: Error only appeared when I do this in MATLAB 2011a. No error appeared when I do the same on MATLAB 2010b.

PPS: I suspect that something was modified, as I did not have the same error message earlier before.