SOLVED!!!
alrighty, I was having the same problem and I found a solution...
I'm using msn live with msgr plus and stuff NG plugin...
I had also recently installed IE 7...
Every few minutes of using msn messenger it would freeze and the window would go white..
then I did I little testing and alot of research to find out that it's actually IE that's causing the problem...
basically, microsoft have set IE to constantly check a couple websites and these websites are on the crappiest server in the world apparently cause if you try to access them you end up waiting forever and usual end up crashing your browser...
and since msn messenger is built on IE technology it uses IE constantly!
so with that being said... all you have to do to FIX THE PROBLEM is change a couple options in the registry..
goto run and type regedit then hit enter
then naviagate to this key..
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
there are 4 things to change...
Default_Page_URL
Default_Search_URL
Search Page
Start Page
these will all be set to some msn.com or microsoft site... simply change them to "about:Blank" (without the quote marks) and then reboot. And tada problem solved
good luck I hope this helps!