[ic] Driver 'mysql' installed? error

[Jonathan Soons]

I tried to install the demo catalog using mostly the default suggestions
(and I choose to use mySQL when prompted). I get the following error when I
try to start interchange.  


root@Ultra:/usr/local/interchange# su interch
$ pwd
/usr/local/interchange
$ bin/interchange restart
Low traffic settings.
Calling UI....
...UI is loaded....
Interchange V4.6.1
Configuring catalog construct...Using MySQL, DSN=dbi:mysql:test_construct.
construct config error: connect failed (create) -- unknown error. Driver
'mysql' installed?

MySQL is working fine on it's own and it has a user named interch.
What am I missing?