There may be nothing wrong, but there is something in your setup that triggers the problem. I had the same problem with a certain website (my own ****ing forum). It just wouldn't work with my internet provider and my router. Only in that combination. A friend of mine had the same (expensive) router and internet provider and the same problem.
So there may not be a defect, but it could be very well that another router or another OS could solve the problem.
But you have to want that... That's why I asked if you had another PC, for expermenting
