IE9 seems unable to 'see' my localhost server

I’ve been running a ‘localhost’ Apache server on my Win7 machines (and previously on WinXP) for several years. I mainly use Firefox as my development browser, but of course I have to be able to test with others, particularly IE.

Recently, on one of my computers, for no obvious reason, IE9 is unable to ‘see’ the localhost files. If I try to load one the screen remains blank and the ‘spinner’ on the tab just goes round for ever. It’s not the files themselves, because if I upload to a remote server they will load as usual. I’m not aware of having had this problem before. The same thing is happening with Safari, but not Opera. I’ve just reinstalled Opera, so perhaps it’s worth trying the same with the other two.

Could there be something I’ve overlooked in the setting up of my Apache server ? Or (more likely) something I’ve inadvertently changed.

Later: Reinstalling does appear to have resolved this problem. For Safari a ‘repair’ did the trick in a few seconds. Uninstalling and reinstalling IE9 is more like hard work, I hope I don’t have to do it too often.

How is your local DNS, host, or lmhost files configured? Do you have local host or 127.0.0.1 configured or any other reference to local host set in these files?

This smells like a routing issue.

Thank you for your reply.

Local host (127.0.0.1) is set up in the Apache config files and the Windows ‘hosts’ file. It’s worked reliably for a long time, and I’ve only recently noticed any problems.
Re-installing IE9 worked for only a short while, then the problem returned. I have an extension to Firefox called ‘IE Tab’, which allows me to switch rendering engine inside a Firefox tab (and which again I’ve used for a long time), but I’m wondering if the latest version is causing some upset in IE9. So my next step will be to disable it.