I did an undergraduate in Comp Sci myself and found it pretty boring. Then I did just a straight comp sci MSc, which was horrendously boring. I quit the course because I just didn't see the point of me doing it, it was not what I wanted to do with my life.
Fortunately, I then came across a MSc in a specialised field of comp sci that really did interest me. So I went for that course, graduated, and I'm currently writing up my thesis for PhD in the same field.
I guess the moral of the story is that computer science is a VAST field and you should try and look all around it first to see if there is anything that might interest you... you never know :)