Carbidopa/Levodopa/Entacapone Versus Immediate Release (IR) Carbidopa/Levodopa on Non-motor Symptoms in Patients With Idiopathic Parkinson's Disease and Demonstrating Non-motor Symptoms of Wearing Off

Inclusion Criteria: * Be aged 30 to 85 years. * Be male or female - female patients must be either not of childbearing potential (defined as post menopausal for at least one year or surgically incapable of bearing children), or must be practicing contraceptive methods as outlined in the protocol. * Have a clinical diagnosis of idiopathic Parkinson's Disease, exhibiting at least 2 of 3 symptoms (rigidity, resting tremor, bradykinesia) * Have non-motor symptoms of end of dose wearing off i.e., the presence of at least one non-motor symptom of Parkinson's Disease which improves with the next immediate release (IR) carbidopa/levodopa dose as determined by the Quantitative Wearing-Off Questionnaire 9 and investigator's assessment. At least one non-motor item has to show a severity of at least 2 points (of a maximum of 4) and show an improvement of at least 1 one hour after immediate release (IR) carbidopa/levodopa administration. Also there should not have been a deterioration of 1 point or more in another non-motor item.(all criteria must be fulfilled) * Be taking a stable dose of immediate release (IR) carbidopa/levodopa for at least 21 days prior to randomization at an equivalent total daily dose of immediate release (IR) carbidopa/levodopa between 300 to 800 mg. Dosing should be either 3 to 6 times per day. Exclusion Criteria: * Have a previous history of being non-responsive to entacapone or tolcapone treatment or having experienced a serious or severe adverse event(s) which resulted in the discontinuation of treatment from the previous use of entacapone or tolcapone; current treatment with entacapone or tolcapone or discontinued treatment with either therapy or discontinued less than 60 days before randomization; * Have a history, signs, or symptoms suggesting a diagnosis of secondary or atypical parkinsonism; * Have unstable Parkinson's Disease requiring frequent booster doses; * Disabling dyskinesias, indicated by a score of greater than 1 on Unified Parkinson Disease Rating Scale question #32, or a score of greater than 1 on Unified Parkinson Disease Rating Scale question #33; * Have a history or current diagnosis of psychotic features according to the investigator; Other protocol-defined inclusion/exclusion criteria applied to the study.