EVariantError 'Invalid variant type conversion'

I have a Delphi 1 application that I converted to Delphi 2.  It is a
front end to an Oracle database.  I had to do some tweaking of the date
formats recently and ended up getting rid of the Query Fields and using
the Column Definitions in the dbgrid component instead.  Once I did this
(at least I think this was the time frame), I noticed that my "select
name,... from ... where name like 'something%'" queries that do not find
anything will cause an exception that I have not seen before
(EVariantError 'Invalid variant type conversion').   I have three
locations in the code base that use a similar query and two of the three
result in this exception, the other one will allow the code to fall
through to an 'IF' that checks to see if the 'RecordCount' is zero and
display the appropriate message.     Any ideas why I am seeing this
exception, and how to get around/work with it?

Thanks for your time,

-Craig Coles