There are many issues regarding IE7,check theses forums and read the many complaints.
Go back too IE6 or another browser,check this LINK
After downloading IE7 I find that when I open a new application (new window), my browser does not stay on what has been opened but jumps to one of the other open windows. It drives me nuts -- I may have 10 windows open at any one time and it arbitrarily hops to another open window (it does open the window requested, but brings an already open window to the forefront, sometimes skipping thru several windows in a matter of a second before landing on one). I've scanned for viruses, but honestly feel this is something related to IE7 as it was never a problem prior. Anyone know of this issue and have a resolution for it?