cordless mouse wheel jumpy

I bought this Walmart special, a Lexma cordless mouse I thought would be great with the scrolling wheel, with 2 buttons to advance or go back a page.

I first used it on my desk top winxp, but since day one, scrolling makes me a nervous wreck. Scrolling either up or down a page makes no difference, it jerks & jiggles up & down quickly so that I'm not getting anywhere.

I've changed the batteries, cleaned it by blowing on the bottom of it. It has a red flickering light on the bottom, never found any lint in it yet. All the buttons & right & left click work fine, just the scroll wheel for page up & down gives me annoyance!

I'm now trying to use it on my new laptop win7, but it does the same thing....guess I'll have to get used to the touch pad now...no choice! Any light on this? I've gone into the control panel & dithered with how many pages to turn at one scroll, but it makes no difference.

There was no program for this mouse, just a usb plug-in with a green light.