Failure migrating wiki to Mountain Lion Server with wikiadmin, value is out of range for type integer

Question

We are trying to migrate our 10.6.8 wikis from the OS X Server to our new Mountain Lion OS X Server.  I am using "wikiadmin migration -r <collaboration directory> -g <wiki name>" to migrate each wiki individually. We have about 30 wikis in the old server, three of which fail to migrate, all with the same problem (below). The process runs successfully for a while, but ultimately fails and rolls back the transaction. It appears there is some problem trying to generate a unique filename, perhaps for some of the uploaded files?
Has anyone else seen this error? large amount of pages, content, and attachments in these wikis and just recreating them in the new server would be a monumental task. Some of these attachments include videos and other large files, not sure if that might contribute to the problem.
=== wikiadmin migrate output log ===
Aug 29 13:25:11 gslcwiki.local wikiadmin[54032] <Debug>: [PGCConnection:233 7e7e1180 +0ms] Executing query [INSERT INTO entity (uid, tiny_id, entity_type_fk, short_name, long_name, description, create_time, update_time, createdby_user_fk, updatedby_user_fk, ownedby_uid_fk, owner_entity_type_fk, is_hidden) (SELECT uid, tiny_id, entity_type_fk, short_name, long_name, description, create_time, update_time, createdby_user_fk, updatedby_user_fk, ownedby_uid_fk, owner_entity_type_fk, is_hidden FROM master_entity_scratch_20120829T132314 WHERE entity_type_fk='com.apple.entity.File')]
Aug 29 13:25:11 gslcwiki.local wikiadmin[54032] <Debug>: [PGCConnection:181 7e7e1180 +151ms] Query result is [PGRES_FATAL_ERROR] rows returned=0/updated=
Aug 29 13:25:11 gslcwiki.local wikiadmin[54032] <Error>: [PGCConnection:148 7e7e1180 +0ms] Error in TXN: Error executing query [INSERT INTO entity (uid, tiny_id, entity_type_fk, short_name, long_name, description, create_time, update_time, createdby_user_fk, updatedby_user_fk, ownedby_uid_fk, owner_entity_type_fk, is_hidden) (SELECT uid, tiny_id, entity_type_fk, short_name, long_name, description, create_time, update_time, createdby_user_fk, updatedby_user_fk, ownedby_uid_fk, owner_entity_type_fk, is_hidden FROM master_entity_scratch_20120829T132314 WHERE entity_type_fk='com.apple.entity.File')]: ERROR:  value "109120715161" is out of range for type integer
          CONTEXT:  PL/pgSQL function "uniquify_filename" line 7 at RETURN
          PL/pgSQL function "trg_update_entity_filename" line 23 at assignment
                    0   CoreFoundation                      0x00007fff93b67716 __exceptionPreprocess + 198
                    1   libobjc.A.dylib                     0x00007fff95aaf470 objc_exception_throw + 43
                    2   PostgreSQLClient                    0x00000001026ff9ae -[PGCConnection checkResultOK:forSQL:] + 360
                    3   PostgreSQLClient                    0x00000001026ffec3 -[PGCConnection executeQuery:] + 223
                    4   wikiadmin                           0x000000010269d586 wikiadmin + 66950
                    5   PostgreSQLClient                    0x00000001026ff5f7 -[PGCConnection transactionInBlock:onError:] + 147
                    6   wikiadmin                           0x000000010269cd86 wikiadmin + 64902
                    7   wikiadmin                           0x00000001026a025d wikiadmin + 78429
                    8   wikiadmin                           0x00000001026924c8 wikiadmin + 21704
                    9   libdyld.dylib                       0x00007fff912857e1 start + 0
                    10  ???                                 0x0000000000000006 0x0 + 6
Aug 29 13:25:11 gslcwiki.local wikiadmin[54032] <Debug>: [PGCConnection:320 7e7e1180 +0ms] Executing update [ROLLBACK]

Answer 1

Okay, so a little more detail for you…
If I can manage to restart the server without the wiki service on, everything else seems to work fine (including the web service running the default home page) and "serveradmin fullstatus wiki" will report that the service is stopped.
But as soon as I try to start the wiki service, it never finishes, and it prevents the web service from working properly anymore. i.e. I get a 502 Proxy Error instead of the OS X Server default home page. It's after the attempted wiki start that "serveradmin fullstatus wiki" starts to give the
serveradmin[2373:707] outstanding requests are: (
        Command = getState;
        Module = "servermgr_wiki";
        Timestamp = "2012-10-25 16:22:15 +0000";
error. And then I can't stop the wiki service - even "serveradmin stop wiki" gives the same "outstanding requests" message.
This time I tried to stop the wiki from Server app and I got this error:
An error occurred on the server while processing a command.
The error occurred while processing a command of type 'getState' in plug-in 'servermgr_wiki'.
If it's helpful at all, I've notice the following in my log files that seem related, but I have no idea how to fix - it almost seems lie the migration of the wiki failed from 10.7 to 10.8:
collabd[767]: [CSConnectionPool:141 6a92000 +14027ms] Schema is STILL out of date (14 < 69) after launching wikiadmin, update failed! collabd will refuse to run until this is fixed.
I'm really pulling my hair out over here, and have no idea what to try next?
Anyone have any suggestions?
Thank you!