If you run ASPRunnerPro-generated application on the Web server with integrated authentication (NTLM) turned on you may find that autosuggest popup presents a login window every time you type a letter into the search box. This appears to be a Firefox bug which is not fixed yet.
Here is the suggested workaround:
You have to go to your Firefox address bar and type about:config. This will bring up the internal config editor, which allows you to set all kinds of properties that influence Firefox’s behavior. Look for the key called network.automatic-ntlm-auth.trusted-uris. Set that key’s value to a comma separated list of servers you want NTLM auth for. So if your internal sites are on servers called Larry and Mo, use “larry,mo”. You can also add the same value to the key network.negotiate-auth.trusted-uris. It’s unclear to me if that second one is required, but I set it, and everything works. Now NTLM authentication works like a champ, and authenticates automatically.
Source: Patrick Cauldwell's Blog
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