Why Alan Johnston was released

According to a very interesting post at Israel Matzav*, there have been reports that Hamas have paid money to the Dugmash (Doghmush) clan, AKA Army of Islam, who held Alan Johnston. The blogger says that, as the clan also hold Gilad Shalit, it is unclear whether they were paid to free Johnston or hold Shalit. However, some reports say that Shalit is in fact held by the Durmush clan, AKA Islamic Army (who have also held Peruvian journalist Jaime Razuri, and were paid $1 million to release two Fox News journalists they held late in 2006). Can anyone tell me, are Durmush and Dugmush the same folks?

* Apologies for wrong link - link now fixed - go read!