If it's a Windows system, there'll be a bit in the Control Panel that'll shut off the touchpad's fancier functions - tap-to-click, tap-to-drag, etc. - which is what it sounds like you're having the trouble with. Turning all that lot off will change the touchpad into a simple pointing device, leaving clicking and dragging to the buttons, as God intended. (And if it's not a Windows system, there's probably still such a thing, I just don't know where to find it.)

The "plug in a proper mouse" suggestion's a good one too, if you've got the real estate for it. I usually use one on my tiny netbook simply because the touchpad buttons are so ludicrously small and wrong-placed. It's a Kensington SlimBlade multimedia mouse, which doubles as an iTunes remote control - not a function I use often, but I do like the way the wireless USB dongle stashes inside the battery compartment when not in use.