i think i found the culprit code.
alias notice.beep {
if (($inwave) || ($inmidi) || ($insong)) return
if ($_optn(5,15) == 0) return
var %beep = $_optn(1,16)
if (%beep == 1) beep
elseif (%beep) .splay " $+ $readini($mircini,n,waves,$1) $+ "
}

now to figure out how to disable it without disabling the script since it uses notice.beep in many places.
i'm guessing it started doing the flashing due to moving flashing into sound events since it previously did nothing but blink the icon which was acceptable. if you have pnp 4.22 to look at i found it in last.mrc, any ideas on how to disable that bit of code without messing up the script would be appreciated. sorry khaled for calling this a bug.