Could be, but i can not check with windoof, i dont have one
I played around a little bit:
If you place all components in one row or one column everything is ok, the taborder is respected
Two tedits, one tmemo and two tedits in a column and then in a second column four
more tedits and you get this behaviour. The focus will jump from tmemo to one of the tedits in the second column and will never reach the tedits under the tmemo
I can clearly reproduce this