the log shows you're using EAP authentication. ms vpn's only like require-mppe, you have to refuse the other authentications:
that would go in the /etc/ppp/options.pptp file.
if you're using network manager, go to the advanced settings window, and make sure only MSCHAPv2 is checked. uncheck the others (pap, chap, mschap, eap).
---------- Post added at 05:52 AM CST ---------- Previous post was at 05:46 AM CST ----------
oops, while your in the advanced window, also enable the mppe stuff.