Install on Demand errors

Help. I keep getting an error while online whenever i go to a website that wants to use the install on demand feature of Iexplorer 5.0, I get an error that says “Install on demand has detected an error. Object doesn’t support this property or method.”
I’ve searched all over the microsoft knowledge database but can’t find any answers. I’ve tried uninstalling, reinstalling, redownloading…and every other kind of -alling or -loading but get nowhere! I thought I had it because I was able to get my windows update to work again but that didn’t have anything to do with it, I guess. I’m getting frustrated so please help soon!