Why do I have to reset my router every time I wake up my mac?

Ok, this is getting both old and worse. Everytime I wake up my mac, I have to reset my wireless (netgear) router to get the mac to find it. Sometimes it take a couple of tries. Once the computer sees it, everything works perfectly.

The problem is that we have four computers running on the network. Sometimes the others will be working fine when mine can't find the network (sometimes its the other way around).

I believe everything is set up correctly in the router settings, but if you have any ideas I'm interested in checking them out.

 

I assume you're talking about lan connections here. If the wireless connection is dropping out it could be the wireless card in the Mac, the router itself, interference from other equipment using similar frequencies (or even harmonics of those frequencies), or physical interference (such as walls or other obstructions).
If the other Macs are connected wirelessly and yours isn't, the problem is not the router.
Check your Airport card is seated correctly. Turn off or remove cordless and mobile phones, maybe even microwave ovens etc. If possible, try a wired connection to see if that eliminates the problem.
Try a ping test - that will check the physical connection.