Informix Error -243

The error -243 Could not position within a table (tracking.nhawb)

The database server cannot set the file position to a particular row within the file that represents a table. Check the accompanying ISAM error code for more information. A hardware error might have occurred, or the table or index might have been corrupted (truncated). Unless the ISAM error code or an operating-system message points to another cause, run the oncheck utility (secheck with IBM Informix SE or tbcheck with IBM Informix OnLine) to check and repair table and index.

Possibilities of the error.
1) Locking issue.
2) Corruption.
3) No space.

Comments:
1) Per our coversation, you folks use "LOCK MODE TO WAIT", in this case
if you don't specify the time, the lock will be held till the user
completes the session. This looks like the possibility of your problem,
because by now the problem should have gone away.

2) Corruption could be possible, I will give you the oncheck command to run during
off peak time, to check the table's consistency. If you have the copy
on development box we can run it on that box to find the time it takes
to complete the command.

3) You have enough space, so there is no issue with disk space.