Outlook 2007 signature issues with images

Hi,

I have an HTML signature file which I use with my outgoing emails.  This 
file contains a couple of images.

We were with outlook 2005, which automatically embedded any 'local' images 
to the email, so the recipient could see them.

We have just upgraded to Office 2007.  For some reason, Outlook 2007 does 
NOT embed these images, but simply leaves the link as c:\whatever. 
Obviously my recipients are not going to have these files on their PC's!!!

Anyone got any ideas?  If I create the signature manually in outlook then it 
seems to work OK, though when you look at the HTML it generates it's really 
not what I'd call HTML!  Still I really can't see why it can't do the same 
thing that outlook 2005 did, ie automatically embed local images within the 
html.  We have a system centralises the generation of signatures and changes 
them regularly, so performing the signature changes manually on each persons 
outlook really isn't an option.

Help gratefully accepted!

Dale.