floating point error or match type issue??

Hello again,

I thought I had this figured out from my last inquiry but this one I just cannot understand.

Attached is my workbook with references to 2 sheets ELEV and KALK. In the KALK sheet, the 2 cells highlighted in yellow should be returning "-03" from the table in sheet ELEV. At the moment it only working for some elevations but not this one. all number cell in the formulas are being rounded to 3 significant figures, however the match is still not working (the rounding was the fix last time). I tried match type -1 and that really didn't work.

I hope this isn't some other Floating point error issue.

regards,
David