>Found a solution, and it was not pretty. An unistall/reinstall of OE - no help. Found a .REG file on the net for OE, and merged it - better, I had a missing entry it seems. Made IE and OE defaults for the system, now the code works with IE and OE. Went back to Mozilla, and made it the default browser and mail client. Now it all works. Whew.

I had a similar one while I was using the Mozilla suite, and my mistake was to trust IE. It has, somewhere in the options dialogue, a selection of default email clients - I selected Mozilla, and forgot about it. Then later I discovered nothing was properly reacting to mailto: links, except when they appeared within Mozilla itself. Then I installed SP4 (on W2k) and then it kept popping up OE (which I have never used, and surely haven't opted to install it - it's a virus).

Eventually I went through options somewhere in Mozilla itself and found where it registers itself as the default email client, which now works from pretty much everywhere except Excel (where I've even lost the Send bar in the File menu, and while it was there, the email related bars were gray), Word (got the Send menu, but email options grayed out), but it works from Access, Visio, OpenOffice (including my favorite "send ... pages as PDF attachment). I'm on Mozilla Thunderbird now, but the behavior is the same as it was with Mozilla suite.