If you're using XL2007 use COUNTIFS over SUMPRODUCT
If running pre XL2007 use concatenation on '85_08', let's assume column C is available:
'85_08'!C2: =$A2&":"&$B2
copied down to C10800
Your SUMPRODUCT then becomes a standard COUNTIF
=COUNTIF('85_08'!$C$2:$C$10800,'09 YTD Auto Claims'!G38&":A")
Less elegant but more efficient.
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