My b2evolution Version: 1.10.x

Hello,

I am trying to upgrade from b2evolution version 1.10.2 to the latest (2.4.7) stable reslease. Every time i get htis error :
Table 'evo_skins__skin' already exists(Errno=1050). deleting that tbale only results in an other error message, claiming another table allready exists.

Restored allready old database (back to 1.10.2), downloaded the latest release again, but the problem keeps popping up.

I am quiet sure nothing is altered to the orignal database structure.

Someone any ideas? I have no clue why it won't upgrade...