Thanks for the bug report. As mentioned in the above posts, this was due to a change in mIRC many versions ago. Unfortunately, it is difficult to undo changes like this as scripts written since then have adapted to the change.
I could change $rawmsg so that it contains the full line, which it should in this case. Although, again, any scripts that currently use $rawmsg in on CHAT, will need to be updated to remove the "ACTION" and "SOUND" (which is the only other CTCP message that behaves the same way - no other CTCP messages are filtered in chat messages) prefixes from the message.
