public folders migrated from Exchange 2003 to 2010

I have a few issues with my Public Folders that I migrated from our
old Exchange 2003 SP2 system to our new Exchange 2010 system.

I replicated the public folders and moved the hierarchy to the new
servers. I do not have any replication configured on any of the public
folders.

Due to error messages that users were reporting in their Sync Logs
regarding Forms, I moved the Organizational Forms system public folder
back to the Exchange 2003 system.
- Since this system folder is empty and Exchange 2010 doesn't require
it, can I just delete it?

I have also dismounted the Exchange 2003 public folder store. I did
this in an effort to make sure nothing was still "hooked into" the old
public folders.

On the Exchange 2010 system, I'm seeing strange things:
- Up until a couple of months ago, I could run the PowerShell command
"get-publicfolderdatabase <dbname>" and see values for the
DatabaseSize and AvailableNewMailboxSpace fields. Now these are
showing as blank.

- I'm seeing odd errors like this in the Event Log on one of the
Exchange 2010 servers (oddly, NOT the server where the public folder
database resides):
Log Name: Application
Source: MSExchangeMailboxAssistants
Date: 12/17/2010 9:04:24 AM
Event ID: 14031
Task Category: FreeBusy Assistant
Level: Error
Keywords: Classic
User: N/A
Computer: gfexmbx02.corporate.gannettfleming.com
Description:
Unable to find freebusy public folder: EX:/o=Gannett Fleming, Inc./
ou=Exchange Administrative Group (FYDIBOHF23SPDLT) on the server:
GFEXMBX01.corporate.gannettfleming.com for the user:username:
57194159-8dc6-4675-97e8-fb93a511ade0:77ca00af-1f32-4cb3-b183-
f5625f03559f:GFEXMBX02.corporate.gannettfleming.com with legacy DN: /
o=Gannett Fleming, Inc./ou=Exchange Administrative Group
(FYDIBOHF23SPDLT)/cn=Recipients/cn=username

These started appearing about the time that the mailbox database on
the OTHER server started throwing "no database connections are
available" errors, and I rebooted that server to resolve that.

- on the OLD server, where the the OLD (unmounted) public folder store
resides, I'm seeing a mail queue in a retry state that is full of
public folder messages from the NEW public folder store: Backfill
Requests, Hierarchy. I understand that these are here because I have
the OLD store dismounted, but WHY is the new public folder database
trying to replicate data to the old one, when I don't have anything
configured to replicate?

I have a few reports from users about odd things, too:
- one user can't edit her own recurring calendar item in a folder that
she has Publishing Editor rights to
- one user puts appointments on a calendar but no-one else with
permissions on that foldre can see them

I have run the Best Practices Analyzer, and it did not indicate any
problems with Public Folders.

I hesitate to start decommissioning my old Exchange 2003 servers until
I have everything with Public Folders squared away; I'm afraid that if
I do, Public Folders on the new system will be irreparably broken in
some fashion.

Any help would be greatly appreciated - even if it's just someone
pointing me to a website dedicated to public folders & troubleshooting
weird problems! :-)

-RAM