Mailto links in a PDF aren't opening

[jo]

I have mailto links in a PDF which seem to work fine within Acrobat.
Once it's uploaded and opened in a web browser (ie7), however, the
mailto links are dead when a user with Vista/Office 2007/IE7 clicks on
them (Outlook 2007 is default e-mail client) .

I'm using Windows XP/Office 2003/IE6 (Outlook 2003 is default e-mail
client) and it works fine for me.

Does anyone know of a workaround?

Thanks.