Prot# 248.543: Rndmzd, Dbl-Blnd, Placebo-Cntrlld, Parallel Grp Clinical Trial Comparing Fixed Doses of 0.25mg, 0.50mg & 0.75mg Pramipexole(Mirapex®) Admin Orally to Investigate the Safety & Efficacy in Ptnts w/Idiopathic Restless Legs Syndrome for 12 Wks