something weird happened in IE7 today
Edit: This exact issue is discussed in a new Knowledge Base article:
I was stumped today for a good 5 minutes today by some weird symptoms on my primary PC - Vista x64 running, of course, IE7. It took me a good 5 minutes to work out what was causing the problem, but I'm still stumped as to *why* the situation occurred in the first place.
I have 8 home pages. This morning when I clicked on the x64 icon or the x86 icon to start IE7 *two* instances of IE7 opened - one with the first 6 home pages, the other with the remaining 2 home pages.
If I opened the 5 tab set and tried to open one of the two missing pages in that tab set, the system swapped to the other instance of IE7 and opened the missing home page there.
After 5 minutes of messing around and rebooting (which invariably works for weird "what the heck??" situations), I spotted that the 5 tab instance of IE7 was running with Protected Mode *off*. The 2 tab set was running with Protected Mode *on*.
I enabled Protected Mode for the 5 tab instance, shut both instances and restarted IE7, and was able to confirm that the problem was gone.
I can understand why such a situation would result in two instances of IE7 running - you can't have some tabs running with Protected Mode off, and some on, in the same instance of IE7, so now all I have to do is work out *why* Protected Mode was turned off for the first instance of IE7, and on for the second when I didn't do anything to create the situation - the only change I made to the system was an adjustment of auto-logon settings for the Trusted Zone (required for Frontpage to be able to save Web site usernames and passwords).
Edit: I've worked out why Protected Mode was turned off. Protected Mode was turned off for the Trusted Zone, but was on for Internet Zone. This mis-match occurred when I used the "default level" button to reset the Trusted Zone to it's default settings. I didn't realise that Protected Mode is turned off by default for the Trusted Zone - a situation that bears closer scrutiny. As far as I'm concerned, Protected Mode should never be turned off. And anyway, the sites that were being split off were not in a unique zone. On the contrary, the first 5 tab instance had a mix of pages in the Internet and Trusted Sites Zones.