[imp] IMP errors

[AJ]

Hello,
  I have read some posts in the archives on Page Cannot be Displayed errors 
happening with IMP on hitting send after composing email.  I have not
experienced these errors myself w/ IE 6, but some users are reporting it. 
Nothing odd in the logs at all.  Can anyone help as to what to look for in
order to troubelshoot this?
This IMP install is CVS HEAD and using SSL.  As always, thanks.

AJ