Too many 487 messages without answer from Asterisk

I´m getting a lot of messages 487 to almost every call in my network. I think the problem is related to the RE-INVITE. The calls works fine, until one side of the call hangup, then the ASTERISK disconnect one side of the call, and send a re-INVITE (changing the IP for rtp packets), but instead of receive a 2xx response I´m getting a 100 (Trying), then when ASTERISK send´s the BYE to the other side I get the 487 messages.

The question I would like to be answered is: Is it correct that ASTERISK send´s an re-INVITE when it receives a bye in the other leg of the call ?