There is no real solution.  The problem is non-conforming clients.
QP is a transfer encoding, so the user of the client should not need to 
be aware of it.  Unfortunately, some clients, including at least some 
Windows clients and Opera, don't handle QP correctly.

It should work to reply by mail, although due to severe spam-prevention 
measures and firewall issues with the system that hosts the tracker 
there are likely to be delays.  I'm working on that.

It may be possible to prevent Roundup from using QP in this case only.  
I'll look into it but it probably won't be implemented soon.

I had the same problem.

The URL is quoted-printable encoded, spread out over two lines.

I decoded it in a temporary buffer in XEmacs with
M-x quoted-printable-decode-region
and was to able to complete registration with that decoded link.

This just describes my workaround.

I'll let Stephen suggest a real solution.

Adrian

I tried to register for the issue tracking tool.  It sent me the string
to login with to confirm, but the string is bad, the link is incomplete,
and I can't complete my registration.