every time I double-click an Exel file, a new 'occurence'of the application
(v2003) opens (complete with 'read-only/notify' dialog about Peronal.xls),
rather than just opening in the already open application.

I have 2003 & 2007 installed, but have 2003 as the default app for .xls
files

Any idea how I can stop it.

Thanks

M