I have an 06 Duramax with 33K on it.  I've had to replace the fuel filter 4 times already.  I've had to be towed into the dealer twice because the filter clogged up and the engine's governor limited the RPM's to 2K.  The filter life display did not provide any warning.  I rarely fuel up at the same place twice so I don't think its the fuel.  What could be causing this?  

Is the filter getting clogged?  If the trouble is truly a clogged filter, you might have either a load of dirt in the tank or bacteria growing in the tank.

Cut a filter open to see what is clogging it.  Act accordingly.

I don't have an old filter with me now.  I'll do that next time.

What is the appropriate action for dirt or bacteria?

There are diesel fuel treatments that can be added to prevent fungus growths. If there is an excessive amount of dirt or contamination, sometimes it's easier to pull the tank and dump it; clean it out and start over with fresh fuel. It can be time consuming and expensive, to change a multitude of filters with a heavy contamination problem.

Gard