I have the same problem. I copied this from the Error Log:
C:\Users\Helena\AppData\Roaming\.technic\assets/packs/hexxit/icon.png
2014/01/05 15:55:03 [iNFO] Analytics Response [runModpack]: 200
2014/01/05 15:55:03 [iNFO] Error occurred during initialization of VM
2014/01/05 15:55:03 [iNFO] Could not reserve enough space for object heap
I am using the configuration "Always use Beta Launcher Builds" with Memory 1 GB. (Using Stable Launcher Builds does not make a difference).
What can be done?