HSeekFirst problem during import

I have the following code:
IF HSeekFirst(RBL_COMP, COMP_ID, dsComp.COMP_ID) THEN...

where dsComp.COMP_ID is SUN 01

The if statement is triggered despite the fact that there is no record with that COMP_ID in RBL_COMP. There is however a record with COMP_ID = SUN&01.

If I change the space in "SUN 01" to e.g. SUN*01 or SUN?01 I get an integrity error but if I change it to SUN101 the program proceeds just fine.
What am I missing?
Thanks
Garry