[horde] Undefined index: driver in Auth.php on line 229

[Dave Anderson]

Hello,

I have set up Horde 2.2.3 and Imp 3.2.1, but I am getting this error

Notice: Undefined index: driver in /var/www/html/horde/lib/Auth.php on line
229

when accessing the horde page. I'm pretty sure it's session/Auth related, as
when I access the imp homepage, I get

Notice: Undefined index: driver in /var/www/html/horde/lib/Auth.php on line
229

Notice: Undefined index: driver in /var/www/html/horde/lib/Auth.php on line
229

Warning: Cannot add header information - headers already sent by (output
started at /var/www/html/horde/lib/Auth.php:229) in
/var/www/html/horde/lib/Secret.php on line 144


before getting the imp login page. If I then login, I get the same errors
again on a blank white page, but if I refresh that page I get a normal mail
inbox with no errors. This then seems to work fine, and if I go back to the
horde homepage I get a proper page with mail/address book/calendar options.

I'm not really sure what's going on here. I have auth set up for through
imp, so maybe the first horde error is because I've never accessed imp at
that point. However, if I go straight to the imp page, I still get the
errors described above.

I guess it's just something I've missed in the config - any ideas?

many thanks for any help
Dave