There are four things I would try
Clear cache-every time you visit a website site it leaves a little copy of itself behind. By itself it's like a piece of paper, but if you put enough pices of paper in front of a door-it won't open. I would try this first especially if you have never done it before. steps to clear cache for IE 7
From the Tools menu, select Internet Options...
Choose the General tab.
Under Browsing history, click Delete...
Next to "Temporary Internet Files", click Delete files...
Click Close, and then click OK to exit.
If that does not work check to see if your explorer add on's are disabled. steps to do so:
Open Internet Options by clicking the Start button , clicking Control Panel, clicking Network and Internet, and then clicking Internet Options.
Click the Programs tab, and then click Manage add-ons.
Look for the add ons associated with the page/site you need to access and select enable.
Note that the changes you make will not take effect until you restart Internet Explorer normally.
Next I would check third party cookie enablement steps to do so-
Click Tools then Internet Options.
Click Privacy.
Click Advanced.
Click to check mark the box next to Override Automatic Cookie Handling.
Click the Accept radio button under First-party Cookies.
Click the Accept radio button under Third-party Cookies.
Click to check mark the box next to Always Allow Session Cookies.
Click OK.
Click OK again
Close and reopen your browser to activate the changes
Lastly I would check your firewall settings-this is especailly true if you have EZ firewall, or EZ armor or if you recieve a 1040 error. They are commonly supplied by comcast/road runner cable.Nothing wrong with these systems, they are very, very effective at blocking things .Hence the problem.
hope this helps.