Just execute
//echo -a $finddir($mircdir,*,0,0,echo -a $finddirn : $1-)
reports this for me on the 7.51 beta:
1 : C:\mIRC\whatever1
2 : C:\mIRC\whatever2
...
14 : C:\mIRC\whateverN
14
6.35 behaves the same though.
Edit: $findfile also has the problem, and it is related to $finddirn or $findfilen, if not used, the problem does not occur.