Possible IE7 problem

[speckytecky]

I have a notebook with an up to date IE7 running on it but recently clicking on e-mail addresses in websites sends it into crazy mode. Up to date Norton AV running, AVG Antispyware active. No problem clicking on URL's, they open fine but if I click on an embedded e-mail address, for a start my default e-mail programme if not open doesn't open and if open doesn't spring up a new message but also things start to go crazy - like multiple web sites of the one I was on try to open. There is a glitch there somewhere but I can't put my finger on it?