I've had this problem in the past and it's usually down to software, not hardware.
I would suggest closing as many running applications as possible especially Internet connections and e-mail clients.
The reason you get skips is because the program priority is overtaken by another running application. For example, if you get a skip or a jump at fairly regular intervals it could be your e-mail client accessing the network looking for mail.
I would also try a dedicated recording application such as
Spin It Again or
All Sound Recorder XP.