...and try pushing it in (towards the center of the bottom bracket shell) with a little more force than you'd normally apply as you turn it.

also...do you have a fixed cup tool? (if you don't, go spend the $20. you'll be happy later ps...measure the distance between the flats...it's is either 32mm or 36mm. if you're lucky your lbs will have the double sided tool with both....mine only had a 36 with a bb pin spanner on the other end that i already have)

also...are you turning it the right way? (is it plugged in?)