Images/Icons & links broken in email filter subscription template

HTML filter subscription emails have broken links and the images do not appear. The source of the message shows that a base href is set (looks correct) and all of the links and image references are relative (thus relying on the base href). Apparently Outlook 2003 does not support base href tags, because the images and links are broken. I saved the contents of the email as an HTML and opened it in Firefox 1.5 and Internet Explorer 6 (WinXP/SP2) but the links and images are broken there too.

I can't figure out the problem – it looks like it should work but it doesn't. I made some changes to the filtersubscription.vm file in the WEB-INF/classes/templates/email/html directory to no avail (though it seems the .vm file is cached, because subsequent filter emails did not reflect my changes). Do I need to restart the app when changes are made to the email templates?