G++4.6 - destructors not running in a cancelled pthread

[mistahmikey]

I am in the process of porting some software from SunStudio12 C++ to
g++ on Solaris 2.9. Much of this software relies on using a C++
objects to allocate/deallocate resources used in a given scope.  We
rely on the fact that the SunStudio C++ runtime ensures when a thread
is cancelled, the stack at the cancellation point is unwound and all
destructors in the enclosing scope are called. 

This does not appear to be the case in g++ (I am using 4.6, and have
not tested other versions.)  Being new to g++ and the myriad
configuration and compile-time options it presents, I hope I am simply
missing something I need to enable this behavior.  If anyone can
provide any information about this issue, it would be much
appreciated.