mbpro unsual internet disconnect, startup and shutdown.

[hindiakopinoy]

i have a weird issue. sometime, all my browsers would just have difficulty connecting to the internet. at this stage, i would notice my mbpro to be humming loudly, as if struggling. my router seems ok, and indicates connection and my pc is connecting fine. but i could not open any webpage on my mbpro. i could not even open my router's default ip address. so, i would just try to restart. but doing this takes forever for my mbp to shutdown. it's just grey screen for 5-10 minutes. then when it restarts, it's the same thing, another 5-10 minutes of just grey screen. then the apple logo comes out and another 5-10 min. then it will shutdown and restart which then would load normally. i tried checking hardware with disk permission and verify disk and everything is ok.
does anybody have an explanation for what's happening or any solution?
osx 10.7.5
thanks.