Speedup offline MS Domain logins

Im trying to make OSX Lion 10.7.4 work with a Mobile Acoount. This worksso far but when the OSX Client isn't connected tot the domain network it takes to a minute to login. Connected to the domain it wold only take a few seconds.

We are running a .local domain. To connect to this domain I used the Domain Join in Users & Groups preferences. I configured the Active Directory advanced options with following options :

With Create Mobile account at logon (no confirmation of creation)

without use of UNC path from Active Directory to derive Network Home location

With Default user shell

Filled in a hard ip-address at the preferred domain server.

Allowed administration by domain and enterprise admins

without Allow authentication from any domain in the forest (we have only one domain)

Domain search

/Local/Default

/Active Directory/DomainName

/Active Directory/DomainName/All Domains

/Active Directory/DomainName/DomainName.local

To speed up the domain connected logon, I changed de mdns_timeout to 0 in the /System/Library/SystemConfiguration/IPMonitor.bundle/Contents/Info.plist

This works but I need to get the offline login time back to a few seconds instead of minutes so who can help me with that ?