Random Netwrok/Internet problem

[BEn_2600+]

Hi, Im having a random problem with my internet, sometimes sites will load very slowly or not at all, it is very random when it does this and usually Diagnose and Repair fixes this but if that dosent work i need to reboot my router. Im running Windows Vista x64 and a Draytek Vigor 2600G (It also did the same on my old D-Link G624), it dosent ussually affect Games but sometimes I have been booted from games with the ussual connection interupted or similar.

Any ideas will be greatly appreciated.

EDIT: Im with UKOnline if it helps, and ive tried using a static IP (local) and using Open DNS for my DNS server but the problem still exists