From what you're telling me.. it sounds like you're using a kit lens (the 18-55mm lens)
Although not opticly great, it is a bit of a hunter.
There are plenty of lenses out there - look at http://www.fredmiranda.com/reviews/index.php?cat=45
(I post on there as kevmar) . Most of the "budget" canon lenses are hunters... saying that .. a posh L series can be a hunter when it chooses to be (I hire them occasionally when I'm getting in the proper pics for myself when doing Portfolio/Model work) .
Ultrasonic lenses are a bit better... L series are very good... but it depends what you are shooting at.
Looking at the night shots - yeah - it'll hunt. Day shots should be better though.