Mouse double click on single clicks sometimes.

I been having these problems for sometime, I have two Intellimouse Explorers,
About a year ago, I been running into problems where the single clicks on the
left button of the mouse would sometimes cause a double click, And then after
using the other mouse for months, The right mouse button is doing the same,
double click on single clicks at times, Therefore, It's gets frustrating at
times when trying to get the right click menu to apear, Or when your trying
to highlight a file which suddenly opens as a double click, I checked all the
mouse settings on the control panel, That didnt help, then I had it replaced
and they send me two intellimouse explorers, Then about months have passed,
and the problems are acuring again, It seems to me that it could be a
hardware related issue involved with the Intellimouse explorer buttons, I do
a lot of clicking cause I'm always browsing on the net and sometimes playing
PC games, Has anyone encountered problems with there Intellimouse double
clicking when you single click, Keep in mind that all the settings for the
mouse in the control panel are normal, I havent touch any of it, It just
seems that its a hardware problem with the mouse itself.