Nope, cannot reproduce. Cycles through each window as expected.
[edit]
OK, on re-trying, I can.
start mIRC
/server -n
/window -z @temp
<ctrl-tab> goes to the second status window, then back to the @win on the next <tab> (holding down ctrl, as stated).
[/edit]
[edit #2]
Further if I connect the two server windows, join a channel on one, the tab order is rather odd, cycling over some windows twice before returning to the channel.
using
/timer 0 3 scid 1 echo -s $activcid $active
and then ctrl-tabbing gave me:
1 Status Window
1 #test
2 @test
2 Status Window
2 @test
1 #test
1 Status Window
1 #test
2 @test
2 Status Window
[/edit]