I currently have 24 singles and I'm using CGMiner 2.4.1 win.
Well, nobody supports ancient versions of CGMiner. First thing to do is upgrade to BFGMiner 2.4.4 - or at least CGMiner 2.4.4 (but note future versions will likely have serious regressions in BFL support). Inevitably though, it sounds like there's a problem with your modem: software shouldn't be
able to crash it no matter what they do.
Thanks I just downloaded both will will try in the morning with the higher versions and see how it works, I know the same thing had happened with cgminer 2.4.3 when I tried it so I didn't bother keeping it on. I'll call verizon too and ask for another modem just in case but like I said, it's a very strange coincidence that it never crashes with 16 but always crashes with 17 or more, I even ran 16 on cgminer and tried to run 1 more on ufasoft since cgminer doesn't allow multiple instances and as soon as ufasoft miner sent the first ok the internet dropped and I had to go up and restart the modem, tried several variations of this and so long as the number between the 2 miners didn't surpass 16 the modem didn't crash. If nothing else works after this, like the other poster mentioned I'll try the ferrite chokes.