If AOL is involved on either end all bets are off. Since you said people using your ISP are having the issue it likely has something to do with them or their software. You can try this initially:
Go to internet options(should be able to right click IEs icon and go to properties. if not go to control panel and go that way.) and go to the advanced tab. Scroll down a ways and look for the java options. Check all 3 boxes(although java console usually doesnt make a difference). Select apply and then go to Security. If you trust that the emails are safe try going to a lower security setting if applicable. If you are using Outlook you can change the security there although it uses default settings from internet explorer. Open outlook goto tools => options. There is a security tab there that you can adjust secure settings. If its on restricted take it off to test and see if this is the issue.
NOTE: IF THIS DOES NOT SOLVE THE PROBLEMS PUT SETTINGS BACK THE WAY THEY WERE OR AT LEASTA MEDIUM SECURITY FOR INTERNET SITES. LEAVING THESE SETTINGS AT LOW LEVELS CAN PUT YOUR SYSTEM AT RISK FOR MALICIOUS CODE.
I have seen problems with people that have AOL or other ISPs that use similar software. They have sent email that would bemuch like what you experianced. The issue was with them and I could do nothing at the time. I no longer know anyone that still uses AOL to test.
The problem appears to be with security or MIME settings, or the software used. You might try reinstalling whatever it is whether its outlook, AOL or the like.
Since you said you can open it as an attachment I'd suspect whatever email client you are using. Check all the settings there before you reinstall. I was going to say ealier the problem could be with the other person if they use AOL. It may not be an issue you can fix on your end.
If someone else out there knows an exact solution I'd like to hear it.
Jason
