Connection drops out every night!

Ok i have a Mac Book (Leopard) at home i connect to a Linksys WRT54G, the only computer that has problems with the router is the mac and it only happens at night! I can connect no problem throughout the day and usually around 10pm the connection gets very slow and drops out. Ive tried troubleshooting with linksys but nothing works. Any ideas what the problem can be? All help would be much appreciated, its actually been like this for a few months but i could always use my other laptop for school work and now that the older laptop broke im pretty screwed.