Business Rules stop working after upgarde to 7506

I had a set of business rules to assign inbound emails from our BKExec-Servers to Admins to check on a daily basis.

Since our database and product were updated to 7506 none of my busniess rules works anymore.

I have made sure only the default rules are in place (none for sites/companies) and also recreated them.

example rule
Criterium:

name of requester is "stg-backup.tbwa-ger.de" (also tried with email-address!)

open
set type   (service request)
set cat      (network)
set subcat   (backup)
set comp (review backup job)
affects business
assign group (backup)
assigne technician

I have also chekd the requester list (deleting duplicate entries etc) but no matter what I do
the rules do not work anymore..

Any suggestions? Has anything apart from the company/dept. specific rule-sets changed?
(The reqeuster stg-backup is not in any dept. so default rules should apply)

Merci

Stefan