COD WAW is lagging excessive COD 4 does not.

COD WAW has way more lag that COD 4 does.  It is not my internet connection.  Other games work fine. I have tried different locale settings with no luck.  The router was removed and the problem remained.  No it is not my internet connection. Remeber COD 4 works fine.

Is there any other suggestions to eliminate the lag?

Thanks