Problems With NULLS in Adaptive Server Anywhere

I have a problem with using the Locate function with ASA 6, when I am
searching for multiple values.  If I specify search values that are all not
NULL, and the database actually contains null values in some subkeys, then
the locate function returns true, and the pointer is positioned on the
record with null values in some of the subkeys, even though that is not what
I had requested.  I should also mention that the locate function should be
using a secondary index.  The secondary index does allow for nulls in the
field values.

I hope that I have explained this clearly enough.

Thanks

Al Willis