ah the old 'netgear flashy modem' issue lol
firmware on the modem might be worth looking at, but it could be a problem with your line at the exchange or the filter your using, the plasticy non flashing wall pluggy in thing
if you can get a different face plate for where the physical connection comes into the house then try that, there only a few quid and can improve the connection dramatically, you want one that has a broadband filter built into it so that the phone and broadband can both go into it, assuming you dont have cable
Most of netgear stuff, certainly the newer is fine for home use.