No it's not, it's related to using too-long userid's longer than 10, look at the topic right before yours:
https://forums.mirc.com/ubbthreads.php/topics/262892/bug_in_identifiers_$address_an
Even though userid's of length 10 are "sorta" supported, it's a good idea to use 9 or shorter, because when the identd handshake fails, they insert a ~ at the front, and that pushes one of your 10 out of the address.
