Cannot remove public foder replicas from Exchange 2003 after moving to Exchange 2007

I'm now in a process of moving from Exchange 2003 to Exchange 2007. At the moment both servers are functional, but all mailboxes and processs (such as OAB generation etc) are moved to Ex2007.

Ex2007 server config: Windows 2003 Std R2 x64, single-server Exchange 2007 installation. Name: Postal.
Ex2003 server config: Windows 2003 Ent SP2, Exchange 2003, the server also is a DC. Name: Pastnieks.

I've replicated my Public Folders to new server and now I need to remove them from the old to begin unistallation of Ex2003. So after succesfull replication I've removed old server name from replica list for every folder. This can be seen on screenshots from both servers: fig1, fig2.

But folders still show in "Administrative Groups - <Ex2003AG> - Folders - Public Folders". As well as in "Administrative Groups - <Ex2003AG> - Servers - <Ex2003Server> - Public Folder Store - Public Folder Instances"

If I try to "Remove replica" in "Public Folder Instances" on old server I receive "Can not remove replica because a folder must have at least one replica". The most interesting part is seen in fig3. If open "Replication" tab for any of the folders, I see both servers in replica list.

I'm now stuck and the only option that I can imagine is delete old server's Public Folder Store record from AD using ADSIEdit. But I'm not sure about the consequences so don't really want to try that. Please help.
fig1.jpg
fig2.jpg
fig3.jpg