Not Enough Memory Message

I just joined my regulaar single player world that i have been running on the snapshots and prereleases with , but there was a ton of lag then minecraft had the not enough memory problem come up
My computer is well enough capble of playing minecraft with all of the setting on max and there is no reason for this message to pop up. after the incident I force updated back to 1.3.2 and i no longer got the error message on any of my worlds

To access this bug just log into a world on the snapshot, please fix this Jeb!