You just have to watch for it, those ID numbers were always prone to changing, particularly when connected as a secondary, if the primary you're connected to goes offline for any reason (reboot, pc owner shuts down to go to bed, <insert any reason you might close computer or winmx>) then you get shifted to a different primary.
This problem is currently made worse by unprotected Hosts file users, who's primaries keep getting flooded offline by RIAA agents... getting word out for hosts file users to use PG2 & this site's blocklist, or switch to the .dll patch, is best thing that can be done to help.