Setting renderer problem

I have two tables that map to different parts of the same data model.
One table contains the row headers for the second table.
In general I have two cell types-
1. text cell that gets a header renderer in the first table and a
wrapped renderer in the second table.
2. icon cell that gets icon renderer in both tables.
My icon cell is currently in the second table.
When the row headers are empty(no data in the first table), the table
is displayed perfectlly.
When I have data in the first table I get ClassCastException which I
traced to the fact that the icon cell is sent to the wrapped renderer.

I understand that setDefaultRenderer is done per table and I don't
understand how a table is rendered right one time and wrong on the
other.

.