Lync for Mac 2011 displays Chinese characters on USB phone

Hit an interesting problem when updating our Macs to Lync for Mac 14.0.4 or 14.0.5. The connected USB phone display changed to a Logographic character set (Chinese or Japanese?):

It appears that this is a problem if you are using the discontinued Plantronics Calisto P540 phone, simply switching the phone to a Polycom CX300 and the problem goes away (reusing the P540 for a Windows user is not a problem).