ector won't
be able to get rid of the button. As a result it can't release the
event handlers of this button either and thus the Lisp garbage
collector won't be notified that the closure is no longer
used. Currently, the only way to avoid these problems with cyclic
references is: "So don't do that!"
<p>
If .NET calls back into Lisp from a "foreign" thread (one that wasn't
created by Lisp), this'll not work in some implementations.
Specifically, <a
href="http://common-lisp.net/pipermail/rdnzl-devel/2006-Janu