Just fixed that same exact problem. The fuel filter was leaking at one of the seams. Replaced it and no problems since. Makes me think Mercedes had a run of bad filters as this seems to be more and more of a common problem with these cars. My car has 36K on it.
95 SL500 Smoke Silver, Parchment 64K
07 E350 4matic Station Wagon White 34K
02 E320 4Matic Silver/grey 80K
05 F150 Silver 44K