Cossacks bug?

[Cunctator]

Dearest fellows,
I left for 2 entire turns a corp of cossacks in Palatinate whose capital (Mainz) was left ungarrisoned by the french player.
A corp of cossacks is considered in the rules as a corp of 1 cav factor, unless for a series of exceptions well specified.
Well, my cossacks had to provoke the conquer of Mainz for the fact that an enemy corp remained for 2 full turns in an undefended french conquered minor, but they didn't.
I must deduct that Cossacks are not able to conquer a minor.
Is it a bug? A deviation from rules? Is it correct?
I would like to know your opinions.

C.

[Cunctator]

Don't answer to my question.
I only had to wait for the end of the land phase and now Palatinate is under my control.
 
No bug.
 
C.

[bresh]

Just so you know.

Its a bug if you where able to conquer a province by a cossak/freikorps.

They are not corps, thats why they dont block movement.

Regards
Bresh