Maybe all of you already know about this problem and how to solve it, but I just want to be sure in that :)
I've got a problem with opening SqueakMap (sq3.10.2-7179web08.12.1.image, fresh install on Gentoo Linux)
it showed me an error same as here: http://www.nabble.com/SqueakMap-Package-Loader-p20334579.html
I've resolved it with running: SMSqueakMap bootStrap.
Now it seems that all is ok. :)