2 anoying problems. cpu (i7 920) overclock/monitor (samsung T240)issue

Hey guys,

Let me start with the first problem.
Every time i overclock my CPU i cannot connect to the Internet anymore. It happens in Windows 7 and Vista. I've tried it several times but each time the outcome is the same. Once i put it on auto then in Windows my internet is back and once i put on manual and edit is a bit its gone.

CPU: i7 920
Mobo: Asus P6T SE
let me know if you need more specs from my pc.

Now for the second problem.
Each time i turn on my pc i get a HMDI/analog message in the left upper corner for the next 40 seconds. i have to turn my monitor off/on to get a normal visual again. same thing happens after i reboot just as the PC goes from off to on.

i am using a Samsung SyncMaster T240.

Hopefully someone can safe me from these 2 problem, because they are really starting to annoy me.