>
> I think the problem could be in update blob field, what do you think ?

Could be.

> I pass a string and want update a blob field, is it possible ?

Well it definately is possible within iSQL, Firebird does the internal
casting providing the string is < 32KB.

Perhaps your VB does not like the mismatch of field types. Modify your
query to not update this blob field and see if it works. If so, you may
need to use parameters for it.

Adam