Lo and behold after weeks of nothing the very minute I moan on the
xsl-list an email comes in:

> Our apologies for the delay in responding - we have been 
> having problems with our mail server (due to spam) which has 
> caused some support request e-mails to be lost.
> 
> We have now dropped the license activation system - in favour 
> of issuing permanent license files (which will work on any machine).
> 
> To obtain a permanent license file please visit:-
>   http://www.marrowsoft.com/XseleratorPLRF.htm
> Enter your registered e-mail address and serial number - you 
> will then be e-mailed a permanent license file.

It's pure coincidence, but a result nonetheless.

andrew