Category Parent-Child Relation lost Virtuemart upgade 1.1.x to 2.0.20b

[csho]

Hello,
i am trying to upgrade a Joomla 1.5 site to 2.5 but first i read i should upgrade/migrate Virtuemart from version 1 to 2. (i trying 2.0.20b, i think this is the last supported for joomla 1.5)

I had a few problems that i managed to pass, but i can figure out how to fix this.
When i migrated my data all Categories became level 0 (top level), as a result all sub-categories to be top-level.
In other words the relation was lost as i check in the database.

I am doing this for a client and i am really furstrated for what to do.
Thanks in advance.