Problems with fle tranfers

Dear all,

I have recently installed openfire ver 3.7.1 on centos 64 bit right now in a test envirnoment created a couple of users .

I am using spark client 2.6.3. our network envirnoment is vlan based so i have many diferent networks

ex. 172.16.2.x, 172.16.3.x, 172.16.4.x etc

the openfire server on the 172.16.2.x network

I just realised that chat works without any problem but i did notice issues with file transfer specially if 2 users are on different networks and its somewht intermittent. for example

when one user send a file to another the othe users gets a message stating the the is a file for him in the chat window but the accept and reject icons are missing.

if the either user logs out and logs in back and if the file is sent again it works fine

also this is somewhat intermittent . sometime it works with no problems sometimes it will not work even after 2 or 3 log outs or logins

this issue is only for file transfer but online chat has no issues at all

In open fire admin console I have proxy enable for file transfer proxy settings

Is there anything I am missing …

i would really apprecite your advice and help

thanks and regards

simon