Autocomplete Slow After 2007 Upgrade

Hi all,

After upgrading from Office 2003 to 2007 when I go to a new message and
start typing an email address there is a significant lag (10 to 20 seconds)
before autocomplete shows suggestions.

I have copied the NK2 file to another location, deleting the file, then re
opening outlook to recreate a new NK2 file then copying it back – No success.

I have also tried the same file on another computer with both outlook 2003
and 2007 and it works fine so it is only this one box.

Any ideas??