Office hang for a while before open file in a mapped drive

I have a primary domain controller that works as file server too, a secondary
DC for redundancy and another server that is file server too.

I have DFS namespaces created so don't depend of server names or ip
addresses, and is replicating some shares.

When a user log on to the domain he gets a couple of mapped drives thought
logon script .bat file that map the drives, one for a share in one server
another in the other server.

Problem is when the user goes to the mapped network drive and opens an
office file, word or excel one, program opens quick and show the page or
spreadsheet but he hangs for some time before we could click or do something
with the document or the program that appears like not responding.

If i map the network drive as \\dfsdomain.local\dfsshare\ and open a file
the office programs can hang up to a couple of minutes.

If i map the network drive as \\domain_controller_ip_address\dfsshare\ the
office programs hang 5 to 20 seconds

If I go to the run menu or in windows explorer address box type
\\dfsdomain.local\dfsshare\ and open the office file it loads instantly and
don't have any wait time

Roaming profiles are activated and redirecting My documents and Desktop to a
share in DFS too, but not mapping a drive and users opening files in My
Documents or desktop works fine too.

Other application such as .pdf or autocad files don't have problem in the
mapped drive.

I've tried without anti-virus program ignoring the folder and even ignoring
in the server AV program the share folder and as no efect.

Network have no latency in ping, only 4 or 5 users logged on to domain and
using shares, we starting a migration to domain, and it works fine with other
apps except office and using directly \\dfsdomain.local\dfsshare\ in windows
explorer address


Anyone can help me on this problem, thanks in advance and sorry for some bad
english