(I strongly suspect Silicon Valley's long term success has more than a little to do with this century or so old policy.)
To me this article strongly implies non-competes are non-enforcable after moving: http://www.crn.com/it-channel/18815740;jsessionid=50NGMBUQKT...
EMC is such a junk yard dog in this area and the allegations are described with sufficient specificity that it sounds like whatever non-completes Karwowska signed outside of California they couldn't be used against her when she presumably moved to Silicon Valley. EMC could only claim nondisclosure and nonsolicitation agreement violations....
Basically, you won't know unless they try to enforce and either succeed or fail.
you could also tell the prospective company of the issue and see if they have a lawyer or anything to check it out.