Q: Premature mouse activity

On the MacBook Air I can be working, using the track pad, and an email, or some other activity will take place without me clicking on the track pad.  A classic example would be typing an email, and all of a sudden it is sent.  Or I might be on a website, and another one opens up.  I don't believe my settings are set to be that sensitive.  I work in an office, but only one other Mac close by, most things are either laptops or thin-clients using VMware.  Thoughts?