I found this link,
http://www.arduino.cc/cgi-bin/yabb2/...num=1213583720, and
http://forum.pololu.com/viewtopic.ph...w=unread#p4218, and it seems to indicate the complexity of checking free RAM.
It might also be related to the intermixing of C++ and C constructs on immature compiler/libraries. I only have anecdotal support, but I've seen it happen before - on Solaris no less!