Herman Cain flip flop on abortion?

Herman said he wants to defund Planned Parenthood - but has no clue how:

Cain said he supports revoking the federal taxpayer funding for the abortion business: “I support de-funding Planned Parenthood. “Tactically how [Congress] does it…I can’t tell you.”

http://www.lifenews.com/2011/03/15/herman-cain-blasts-planned-parenthood-abortion-biz-attacks-him/

Now - he refuses to sign the SBA pledge that all the other historical pro life candidates signed (Romney refused as well, but he also brought in cheap abortions to MA).

Five of the Republican presidential candidates seeking the GOP nomination to take on pro-abortion President Barack Obama in 2012 have signed onto a pro-life pledge the Susan B. Anthony List has sponsored, but Mitt Romney and Herman Cain have declined.

http://www.lifenews.com/2011/06/17/2012-gop-candidates-sign-pro-life-pledge-romney-cain-refuse/

What type of things is in this pledge?

* Select pro-life appointees for relevant Cabinet and Executive Branch positions, in particular the head of National Institutes of Health, the Department of Health & Human Services, and the Department of Justice;

So Herman will appoint a pro-abort, but not a Muslim?