Why are Florida delegates not proportioned?

When you read the CNN email, it states that Romney has to have a majority of the vote to take all of 20 delegates from Puerto Rico.  Why wasn't that the case in Florida where Romney only got 46.4% of the vote?  Not a math genius but smart enough to know that 46.4% does not equal the majority of votes.  So why didn't the RNC demand that Florida award their delegates proportionately?  You can except a challenge in credentials when Florida shows up with all Romney people and most like the Rules Committee will get involved before this over. I would suspect unless the Romney people in FL back down to see this go to the floor for a decision.

This has all the makings of one nasty Convention thanks to the RNC who refuses to use the same rules for all states.  Why have rules if they don't apply to all states?

CNN Breaking News email, 18 March 2012: 

Former Massachusetts Gov. Mitt Romney will win the Puerto Rico GOP primary, CNN projects. 

Puerto Rico’s 20 delegates will be awarded proportionally. However, if Romney finishes with a majority of the vote, he will take all of the delegates.

Puerto Rico's primary comes two days before the showdown in Illinois, where 54 delegates will be awarded proportionally and polls show a tight race between Romney and former Pennsylvania Sen. Rick Santorum. 

Florida100% reporting

Candidate	Votes	Pct.	Del.
Mitt Romney	775,014	46.4%	50
Newt Gingrich	533,117	31.9%
Rick Santorum	222,799	13.3%
Ron Paul	117,104	7.0%
Others	21,613	1.3%