Hi Ivan,
Hard to say in this case what would cause the 488 to be sent. I know there have been several changes over time between those SUs to correct issues in both IPhost libs and SIP stack. So would need to see more specific RTF logs to comment further.
But in that case, you should really open a ticket with the dialogic support team (if you have an SLA-VPUP) tied to that site to acquire support.
If not here a link for information on that:
www.dialogic.com/hmp-sr140-enterprise-software-services
Jeff