Router gone bad or conditions worsening to blame

So I have an old 108mbps netgear router. The problem is the dang thing has to be reset about 5 times a day. The router was fine up until the beginning of summer and then things went south. I think all of these things may be partially to blame.

1. The router had 2 pcs (both xp) accessing it and (then at the beginning of summer) 2 more laptops( one running linux and one running vista) and a wii
2. The ethernet cables don't click when you insert them, they just kinda sit in their making the connection a little suspect.(plastic piece snapped off)
3. Its hotter in the summer and it puts more stress on it
4. Its right next to a 2.4ghz phone set.
5. I changed to wpa encryption from just a mac filter solution

So my question is what is most likely to be the problem and what should i do first to fix it? Should i just get a new router, the exact same one because this one broke? Or a different brand because this one cant handle the load?

Are potentially the loose cables and phone set causing to much interference making me loose the signal?

If i could get any feedback that would be great. Thanks guys