transferring issue


i have asterisk with configured sip extensions works fine.

i have three extensions configured polycom ip 501 like 294 ,218 210.

i(218) am on call with 294. i wish to transfer the call to 210. after , the call is being tranferred to 210. Now 210 and 294 got connected and started conversing… once i do that now in my instrument 218… it shows off hook in the display … and l while seeing the cli prompt it prompts like

Incoming call: Got SIP response 500 “Internal Server Error” back from ( this is the ip address of my polycom instrument).

i follow the following sequence to transfer from my instrument.

2.blind (select)
3.transfering number (210)
4.i press send button

what is the error shows and also how do i turn of the off hook display after tranferring the call ? … Any suggestion will be very much helpfull

I’m getting this same message from my Polycom sets. It doesn’t appear to hinder operation of the phone, but it’s an alarming message just the same. Anyone fixed this?