"at end of table" error message

hi there!

i have a problem with one of my apps, i got an "at end of table" error
message when i execute a query with an insert statement. i got it
exactly in the query1.execSQL line, why can this be happening? any
ideas?

im using an  Oracle8 Enterprise Edition Release 8.0.4.0.0 - Production
version of oracle.

thanks in advance.

eliseo.