Hello. I've literally not slept for 2 weeks trying to solve this problem. I've searched pretty much every where for a solution to this problem and it was pretty much unanswered. Just so no one else has to lose sleep over this, the problem I am describing is this:
During I2C mode there is SDA held high and SCLK held low. You will experience hanging when checking the busy flags, STP, STT, etc. If you are using the MSP430F2274 that comes paired with the RF2500, then because the development board connects the P3.2 to the RF2500, then in order to use the SCLk you need to add P3DIR |= 0x0F before selecting I2C pins ( P3SEL |= 0x06) to disable the device first.
Source: http://processors.wiki.ti.com/index.php/EZ430-RF2500