Just an update: I did try to buy a modem/router to replace my PLDT supplied one. I went to a computer shop across the street from Unitop. The guy who seemed to be in charge would not sell me one. Well, I suppose he would have if I had pushed the issue but he told me it was a waste of money as PLDT would have to come out and install it so they may as well replace the one they supply at the same time.

So PLDT finally came out and 'fixed' the problem. Turned out to not be the modem this time. They spent about an hour on the phone testing and playing with things and then told me it was a 'Manila problem' but they have it sorted now. Its been working for the last 2 weeks anyway :-)