Subject Problem with Firebird/Interbase

I have a problem with one table in a database of interbase.
Well, i can insert new records good, but when i want to delete a
record ( IBConsole ) firebird gives me the next message:

conversion error from string "00000000001"

This error don´t give in other table with a similar structure......

What happening, pleaseeeeeeee????

Best regards

Carlos G.A.

( Sorry about my bad english but i´m spanish )