Dear Niraj
there are a lot of reasons one can list. Assuming now that you use te same printer (hardware etc.) on dev/prod:
a.) is the WWI environment in dev the same as in prod ((same WWI version; same wwi.ini)?
b.) is the layout used in dev the same as in prod (may be somebody still changed WWI layout in dev)?
c.) do you use dynamic text sizing? and is data different which need to be collected in prod in comparison to dev?
d.) which WWi set up do you use? central WWI server and no ? local WWI installation or central WWI server with local WWI set up?
etc. etc. Can you provide may be more information on that. By the way: SAP version might of interst as well (SAP ERP EnhPack ? SP status?). In context of WWI etc. by SP there are roughly 3 - 5 fixes per SP in WWI context (never counted exactly).
C.B.