Minecraft randomly freezes

The batfile wont start up minecraft.

what does it say?

Never mind, i fixed it. Just forgot the "m" next to the numbers.
Also, the pewpew server is up!

Here's a few things you could try (or do all of them if you wish)
Allocate more RAM to java
Get Optifine (I got it, even though I have Quadcore 3 GHz, It makes a huge difference)
Update you Graphics drivers (The latest is 304.48 beta)
Make sure all other unnecessary background programs are closed
Force update for clean install

To allocate more RAM simply create a notepad on your desktop and paste this into it (this allocates 3GB of your RAM)
javaw -Xmx3072m -Xms1536m -jar "C:\Users\Sonny\Desktop\Games\Minecraft.exe" *KEEP THE LAST QUOTATION MARK*
Then save the notepad as Minecraft.bat and then double click the .bat and Minecraft will then run with more RAM allocated.

If all of this doesn't work, Just wait until the next Minecraft update (1.3 on 5th July and maybe the bug will be fixed)