Sadly, I cannot replicate your problem. If I put your formula in a cell and
copy downwards, I get:
=VLOOKUP($A3,pvt90DNet!$A:$AZ,MATCH(pvt90DNet!B$2,pvtCnt90!$2:$2,0))
=VLOOKUP($A4,pvt90DNet!$A:$AZ,MATCH(pvt90DNet!B$2,pvtCnt90!$2:$2,0))
=VLOOKUP($A5,pvt90DNet!$A:$AZ,MATCH(pvt90DNet!B$2,pvtCnt90!$2:$2,0))
=VLOOKUP($A6,pvt90DNet!$A:$AZ,MATCH(pvt90DNet!B$2,pvtCnt90!$2:$2,0))
=VLOOKUP($A7,pvt90DNet!$A:$AZ,MATCH(pvt90DNet!B$2,pvtCnt90!$2:$2,0))
=VLOOKUP($A8,pvt90DNet!$A:$AZ,MATCH(pvt90DNet!B$2,pvtCnt90!$2:$2,0))
The $A3 adjusts as it should. $2:$2 retains its integrity.
Same behavior in 2003 & 2007