Here's the code where it's blowing up:

IF !USED('SETUP')
USE ALLTRIM(oVar.Sysdatapath) + 'SETUP.DBF' IN 0 SHARED
ENDIF

SELECT SETUP

LOCATE FOR ALLTRIM(TableName) == m.cAlias

IF RLOCK()
brow **this browse allows me to look at the table okay, everything looks in order
REPLACE NEXTID WITH nextid + 1 IN SETUP ** this line is where the program bombs off *****

nRetVal = SETUP.nextid
UNLOCK
ENDIF