Hi Hotdog,
I have noticed it disappearing on new tabs too, although I am also using the
Yahoo tabbed toolbar too! I think there is some kind of bug lingering
around.
You can try 2 things.
1. Reset the toolbar layout. Click on the Help icon on the toolbar and
select the 'Reset IE Toolbar Menu' option and then restart IE.(seems to work
for a while though unpredictably other toolbars appear.)
2. Reinstall the toolbar. I haven't tested this, but it appears that the
toolbar gets confused the longer it is used. (It keeps counts of opened tabs
in the registry... too technical?)
Regards.