Horde + IMP installation

["Philippe Clérié" <philippe@gcal.net>]

I am having some problems installing horde and imp from testing.
When trying to load horde I get:

Fatal error: Cannot redeclare class db_sql in
/etc/horde/db_mysql.inc on line 12

Which seems to imply that said class is declared twice in different
modules, which does not seem to be the case. Or that db_mysql is
included twice, which also does not seem to be the case.

I know next to nothing about PHP so I'm hoping someone has already
seen this.

Also, both packages hang on uninstalling (dpkp --purge imp horde)
right after restarting apache. ps ax shows that the postrm script
for the package is "defunct".

Thanks in advance for any help,

Best regards,
Philippe Clérié (philippe@gcal.net)