As best I can remember, I installed them both from tarball. Root's perl is /usr/bin/perl, and /usr/bin/spamd specifies the same perl.
How can I track down and remove the 2.55 installation that's apparently still there?
Usually if this is the case one copy will be installed in /usr/local/* and the other in /usr/*. Check to see if you have /usr/local/bin/spamassassin and /usr/bin/spamassassin.. if you do, you've got the problem.
Typicaly non-root users have /usr/local in their path, but root does not, leading to the "mixed versions depending on who calls it" behavior.
As for clean up, when this happened to me I just went through and manualy rm -f'ed the directories and files out of my /usr/local. Places to check for SA files are /usr/local/lib/perl went, /usr/local/bin/, and /usr/local/share/spamassassin/.
