And also on MSN.com but not on Yahoo!
Moreover I can't do a Windows Update through Internet Explorer. However, everything works fine in Windows Explorer! (In the search panel: view->explorer bar->search and then search the internet).
I've been working on this and I think I'm getting somewhere: I've noticed that if you delete the following registry key and all its content (export the key an all its content first to put it back!):
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility
The problem with the search disappears (you have to restart the browser). However, of course, you also lose all the functionality of the ActiveXs, like flash and Windows update.
Restored the registry key and the problem is back, as expected.
Now you would think that the problem is with one of the numerous subkeys: Tried deleting them all (by editing the reg file, not manually!) keeping just the main key (i.e ActiveX Compatibility with its empty default value) and the problem remains, as if IExplorer is just looking for the presence of the key to continue or not with the hack or other ActiveXs.
That's where I'm at now. I'll keep working on it later. More to follow I hope. Reply if you find something.
BTW I did try do disable all the ActiveXs and it didn't work.