On Sat, 14 Apr 2012 Paul A . Rubin wrote:
In LyX 2.0.1, the box has a handle. If I right-click the handle, I get a context menu that includes the "Settings" submenu, where I can change box size. Changing box size there works for me (Linux Mint 11), as does Edit > Box Settings. Do you get the context menu in your setup?
Thanks for your answer. The problem appears only in versions 2.0.2 and 2.0.3. In previous versions I have no problems.
I have reported this bug (http://www.lyx.org/trac/ticket/8124) and it is being resolved now.