I fixed it, and you'll never believe how simple it was. I launched IE, and (for the first time, mind you) I got a dialog box saying "Google Toolbar is not compatible with IE8 and must be disabled, or check the site for an updated version" (or words to that effect).
There was a button which said "check for updates." I clicked it. It took me to the IE8 Beta 2 Release Notes. Under "Compatibility with third-party applications," it says:
Internet Explorer 8 Beta 2 displays a compatibility warning when certain versions of the Google Toolbar add-in are installed. This issue occurs because Internet Explorer 8 Beta 2 and specific versions of this add-in are incompatible, and the installation is unstable. When you disable this add-in, the functionality that this product provides is removed.
For more information and for updates, visit the following Google Toolbar Web site:http://toolbar.google.com/tbredir?r=ie8_upgrade
I clicked the link and it took me to the Google Toolbar 5 Beta page. I installed it and...VOILA!...I have the Google Toolbar AND the message bar is gone.
What DID happen:
1) Google Toolbar (less than 5 Beta) is not compatible with IE8 Beta 2.
2) If you have Google Toolbar and install IE8 Beta 2 you will get a message bar stating that "add-ons have been disabled
." BUT it will not tell you WHICH ones have been disabled -- One? All? A dozen? AND the Manage add-ons center will NOT show the Google Toolbar disabled
. It will show that it is ENABLED
3) Only after having started IE several times did I get the dialog stating that Google Toolbar was the culprit.
4) I installed Google Toolbar 5 Beta and it IS compatible and the message bar is now gone.
What SHOULD happen:
1) The message bar, which triggers the Manage add-ons box, should state which add-ons have been disabled due to incompatibility. Instead, it states that ALL ARE ENABLED.
2) Launching IE should immediately trigger the incompatibility warning the first time, not after several launches of IE.
If either of the above had taken place I would have immediately gone to upgrade the Google Toolbar.