Thanks for your bug report. I have not been able to reproduce this issue here so far.
Is this happening with a specific event? Or with all of these events?
Can you please type the following command into mIRC and post the result?
//echo -a $os $version $beta $md5($mircexe,2) $file($mircexe).sig $alias(0) $script(0) $dll(0) $com(0)