Samsung Galaxy S2 — Using my phone for internet access

First off, I live out in the boon docks, where the only internet available is dial up.
I use my cell phone for my internet, and recently got a blue tooth keyboard and mouse, and the cable to connect my phone to a PC monitor.
The problem I am having, and I have yet to find a definite pattern, is that randomly the monitor will go black for a couple of seconds to maybe ten or fifteen seconds.
My first thought was something with the monitor, so I tried a second one and still the same thing.
Does anyone have any clue what the problem might be?
The phone is a Samsung Galaxy S2.
Thanks a bunch for your help.