Some customer exit variable not consistently displaying correct output

Hi,

In my query I have 4 customer exit variables which calculate Q1 thru Q4 totals. I also have customer exit variable which calculates YTD.

Problem is that if I refresh my query in Analyzer, all the Q1 thru Q4 are blank, but YTD is correct.

If I re-open the query and execute, then the Q1 - Q4 data is displayed correctly.

RSRT displays correctly all the time.

The only difference I can see is that YTD variable is set as "Selection Option" and the Q1 - Q4 are defined as "Interval'.

Any suggestions?