Yeah, it looks like a file error, are you using any hand code in the source to access the file ?
or is there any other pc's accessing the database as well ? Could be someone has deleted a record you were about to do a put on.
As per the Clarion help, error 33
33
Record Not Available
Usually an attempt to read past the end or beginning of file with NEXT or PREVIOUS. May also be posted by PUT or DELETE when no record was read before the attempted PUT or DELETE.