According to the documentation there is not suppose to be numeric
overflow in python 2.5. However....

If you run a for loop with the range(1, 300000000)a couple of times (for
me 2 or 3 times worked) in the IDLE (1.2.2)GUI . It will cause what
appears to be a memory leak, at least under vista home edition. Haven't
tested out other platforms yet. Vista's logon process will fail to start
security dialog as well if you try to ctrl-alt-del. Which effectively
cripples the system. I haven't tested to see if the condition will get
better over long period of time. I've waited a max of 10 minutes for the
system to respond. 

I tested running the script multiple times under cmd in windows, and it
spits out a memory error after a minute of not responding and then the
cmd prompts will close and the system will begin responding. So it
appears to be isolated to IDLE.