I couldn't either make guiminer to work with my i7-2670QM,
I have no recollection about the error messages.

I use pooler-cpuminer and cuda miner for 555M, win7.
Hash speed is not too good combined Hash is around 37-55Mhas/s.

I have .bat file to start mining:

minerd -o stratum+tcp://YOURPOOL.com:3333 -O WORKERNAME:PASSWORD

Slow but it works.

Teemu