Then create a shortcut pointing to the .jar allocating more memory:
"c:\Program Files\Java\jre6\bin\java.exe" -Xms1024M -Xmx2048M -jar "X:\Path to Mincraft\Minecraft.jar"
It's something worth trying anyway, if you have the memory and a 64-bit system, as it stands to improve performance a bit.
Rollback Post to RevisionRollBack
"When we release a pure bugfix update, people get VERY upset ("NOTHING CHANGED!").. Adding features gives us much happier users. But I do realize that it's only happier users in the short term." - Notch