We, Blizz and her alt, Skysong, were fighting Friggy. Dual hard mode. However, the moment that Friggy entered the portal, he despawned and everything else did as well. To make sure, me and blizz tried a second time, and it happened again. Then i suggested a third attempt, and this time, it worked just fine until the second time that friggy was going to retreat into his ice realm, and again, everything de-spawned.
Also, i was going to place the records of the logs in which it describes the battle, but it was a lot, and i wasn't sure if i should post them or not, so i have this one log:
[mm_snow_plains05:2918]
31.May.2012 21:42:13 :
Frigus despawns.
Not sure if i should have posted more or not...
