Blood tests looking at the kidney funtion is reasonable, and reported to be normal.
I would consider some imaging studies - such as an ultrasound or IVP - to determine if there is a structural lesion leading to the protein.
Other diseases like diabetes or congestive heart failure should be evaluated for. A fasting sugar test can evaluate the former. The latter disease is less likely with the normal echo.
The most definitive test would be a kidney biopsy - however, this is normally considered if the protein is consistently above 2 grams.
These options can be discussed with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
http://www.straightfromthedoc.com