Nat gas is down big. (There's a discussion on the CHKR board about the sensitivity of CHKR's distribution and the price of nat gas). I have also heard that the weather has been mild in the regions that use propane, so that could adversely effect their volumes. One could easily compare the stock price to the other propane MLPs (Ferrellgas, APU) to see if they are also getting hit.
On the last conference call, they were specifically asked about the distribution, given that it is only covered by about 95% of cashflow. As I recall, there was no hesitation about keeping it the same even though they acknowledged that they had to borrow off of the line of credit. But that could have been based off of their predictions for volumes and price at that time.
On another note, there's a blogger who blogs under the name MLPguy who predicted a few weeks ago that the MLP sector would see at least one distribution cut and many think he was thinking of NRGY. Some maybe selling before the announcement, just in case he is correct or had some inside knowledge.
Ferrelgas and AmeriGas are both up today. Ferrelgas trades with an 11% yield like NRGY, but AmeriGas and Suburban have lower yields. Ferrelgas just announced layoffs in Kansas City, where NRGY is also located.