The 225 is full Duplex and I can't see any reason why it should not work. I can only suggest menu, system settings. restore default, and see if that changes anything. What exactly is happening when you do a conference call? Procom have a support section manual here http://support.polycom.com/PolycomService/support/cn/support/voice/soundpoint/soundpoint_pro_se225.html support here http://support.polycom.com/PolycomService/support/us/support/Contact_Us.html worth sending them the question they can only refuse to answer or try to charge you!
Answers & Comments
The 225 is full Duplex and I can't see any reason why it should not work. I can only suggest menu, system settings. restore default, and see if that changes anything.
What exactly is happening when you do a conference call?
Procom have a support section
manual here
http://support.polycom.com/PolycomService/support/cn/support/voice/soundpoint/soundpoint_pro_se225.html
support here
http://support.polycom.com/PolycomService/support/us/support/Contact_Us.html
worth sending them the question they can only refuse to answer or try to charge you!