multimc error

------------- MultiMC Crash Report -------------
Information:
	Date: 06-27-2013 17:00:22
	Operating System: Windows 7 (build 7601, Service Pack 1), 64-bit edition
	MultiMC Version: 4.3.0 jenkins-MultiMC4Windows-77
	Minecraft Version: 1.5.2

------------------ Mod Lists -------------------
Jar Mods:
	OptiFine_1.5.2_HD_D3.zip
		Version:
		Filename: OptiFine_1.5.2_HD_D3.zip

	[1.5.2]ReiMinimap_v3.3_06.zip
		Version:
		Filename: [1.5.2]ReiMinimap_v3.3_06.zip



----------------- Console Log ------------------
Instance folder is:
C:\Users\Marky Bear\Desktop\MultiMC\instances\New\minecraft\

Instance started with command:
"java"  -Xms512m -Xmx1024m -jar MultiMCLauncher.jar  "<username>" "<session ID>" "MultiMC: New" "854x480" "Mojang"

Error occurred during initialization of VM
Could not reserve enough space for object heap
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.
Minecraft exited with code 1.
Minecraft has crashed!