Concurrency violation: UpdateCommand affected 0 register

[Silviall]

Hello,

When I update a datatable row in my application, it generates a concurrency
exception. I am unique user, and it can't be an error of concurrency. I've
read some information about the same problem, but nobody has the answer.
Sometimes it gives me the error "ORA_01722: Invalid Number". The insert, and
delete works fine, only it works wrong when is an update and when it has
"WHERE ....", if it is "UPDATE table SET a=b" it works fine.

Does somebody know what the problem is ?

Thanks for all,

Silvia.