soccertese,

You mention that levodopa works well "until about noon" and "repeat the cycle with sleep fixing the problem".

IMHO this strong diurnal relationship suggests that melatonin may be playing a part in your problem.

"Melatonin ... is a naturally occurring compound found in animals, plants, and microbes.... In animals, circulating levels of the hormone melatonin vary in a daily cycle, thereby allowing the entrainment of the circadian rhythms of several biological functions." [1]

"In patients with Parkinson's disease (PD), MT1 and MT2 expression declines especially in the substantia nigra and the amygdala." [2]

Hardeland [2] lists a wide range of symptoms.

References

[1] http://en.wikipedia.org/wiki/Melatonin

[2] "Neurobiology, Pathophysiology, and Treatment of Melatonin Deficiency and Dysfunction"
Rüdiger Hardeland
ScientificWorldJournal. 2012; 2012: 640389
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3354573/

John