How to setup Invitations in iCal on a Server

Question

Hi everyone!
Since some time now, I'm facing slight difficulties using iCal in conncetion with its built in invitations feature. So here's my problem:
Some how we're not able to send innvitations via iCal to some of our staff members. We have 15 staff members, all using thier own CalDAV Account on a SL-Server (MacPro). As you create an event an want to invite somebody, iCal often doesn't recognize the Person to be invited.
I know that iCal uses the adressbook app to find the people to be invited.
So this is where our second issue arises. We're using a CardDAV Account containing a serverbased addressbook that contains vcards of all employees, customers, partner etc. Each employee has its own Mac mini running Lion.Their adressbook app is set up with this one cardDAV Account. This way we should all be using just one addressbook located on the server right? (this is basically what we would like to have. A single addressbook located on the server containing every vcard we need. Everybody should have the permit to add, delete or modify each vcard contained).
Unfortunately all client-macs show multiple vcards of each vcard located on the server so that I suppose there's something wrong with the syncing process. Also, if someone creats a new vcard on its client within the adressbook on the server, this new vcard isn't published, so nobody else can see it or have accsses to it via iCal.
Any ideas where this issue could come from?
Back to iCal: as we add some staff members to newly created events in iCal, some staff members are recognized by iCal showing the ?-statussymbol, and some are not recognized showing a small lightning-statussymbol. This is an issue we'd likt to fix.
I have to appologize in case you don't get my point. So to make it more clear what we would like to come out with at the end, let me tell you our goal:
We'd like to have a single adressbook located on our server. Each staff member conntects to this adressbook via a single CardDAV (all members will use the same account), so that each staff member has access to the addressbook located on the server and is capable of adding, deleting or modifiying the contained vcards. If a staff member adds, deletes or modifys a vcard, this should be automatically updated to the server an synced to all other staff members.
After this is done, we'd like iCal to properly handle invitations. iCal should recognize all staff member by name and automatically adds its email address. iCal should invite the added staff member to the event, so that the invitee will recieve the inviatation within its iCal only.
If you have any questions regarding my explained issue, please feel free to contact me. This is a rather urgent matter for us, as we're experiencing these issues for about 2 years now...
Looking forward to your answers!
Regards,
Moritz

Answer 1

Since you are showing more than 1 of the same user, I imagine that you have the open directory bridge 'Search for user accounts' enabled in the AB service.
The ? symbol is normal when iCal doesn't know where to lookup the user's free/busy details.
On the client side, perhaps 1 AB entry contains the info needed and the other doesn't.
Instead of typing the name in ical attendees, try dragging the entry from AB.
Try one occurence of a user, then the other occurence of the same user.
I'm thinking when you let ical choose, its grabbing the incomplete entry in some cases..
this might not be the solution, but hopefully puts you on a path towards it :-)