Problem migration IPB 2.1.x to PunBB 1.2.x

I use "PunBB Migration Tool 1.4.0" for migration Invision Power Board 2.1.x on PunBB 1.2.x
In general converting passes successfully, but will not be transformed or do not delete tags
which uses IPB, and PunBB them "does not understand".

That will advise to do?
Will be a new version "PunBB Migration Tool"?