I will be honest and say I don't know much about the the rough cut capacity report, but I was able to run a SQL trace and capture the selection criteria used to generate the source table. (MacolaES)
So you need data in your master schedule file. The report ignores Customer Orders, Purchase Orders, and Forecast order types (in above file). Pulls data from the product load profile, and finally from the Mfg Setup file.
Hope this may help, although it seem everyone else was pointing at the same things.
SELECT msschfil_sql.start_dt, hzplpfil_sql.load_meth, msschfil_sql.ms_qty, hzplpfil_sql.lbr_hr_per, hzplpfil_sql.per_lbr_hr, hzplpfil_sql.mch_hr_per, hzplpfil_sql.per_mch_hr, hzplpfil_sql.setup_tm, hzplpfil_sql.dept, hzplpfil_sql.wc, msschfil_sql.item_no, hzctrfil_sql.wc_desc FROM hzplpfil_sql LEFT OUTER JOIN msschfil_sql ON hzplpfil_sql.item_no = msschfil_sql.item_no LEFT OUTER JOIN hzctrfil_sql ON hzplpfil_sql.wc = hzctrfil_sql.wc AND hzplpfil_sql.dept = hzctrfil_sql.dept WHERE MSSCHFIL_SQL.gen_file = '0' AND MSSCHFIL_SQL.start_dt <= '2005-12-31' AND Not(msschfil_sql.Ord_Type IN ('CO', 'PO', 'FO'))