Ping Problems...

Heya recently i have been getting really bad ping..
About 2 weeks ago, every game at any time of day i used to get a stable 110 ping. (im from UK)

But now, from about 12 (Lunch) - 3 AM I have a ping which is 130 + and changes constantly.
It varies from 130-170.. Changing all the time.. Random people teleporting.. None shots are registering, So i can't play this game anymore,

Just wondering if anyone else is having this problem, or any possible reasons why this is happening ?

- No there is no Other Pcs on my network.
- No im not running any other programs
- No im not DLing while playing
- My ping is fine on every other game i play on but this one.

Thanks O.O