Build limit question

[mdsmall]

In my current game, playing Axis, the Russians managed to kill one of my German tanks. I went to build it back and I see an asterisk beside the unit name and an appropriately discounted rebuild cost. But the unit is in red indicating that I have exceeded my build limit - even though this would be replacing an existing unit. Why can't I rebuild it?

[Sugar]

If you built all the tanks before the arrival of the DAK, you`ll have one additional tank "over" the build limit and therefore can`t buy it back.
Same is possible with the Russians before the Siberians arrive.

The upside is you can buy the cheap tank back after losing the next on low supply.

[Elessar2]

Or cheat & turn on soft builds.

[mdsmall]

It's an appealing idea, but I don't think you can do that in a PBEM game!