I also had the same problem. I found the soulution in Honda Service Bulletin 01-081. One of the main causes is a corroded shifter cable bushing. (Honda P/N 54310-S5A-999). My cost was $11.80 and it only took about 30 minutes to install. The following link details installation.
http://honda-tekh.livetopic.com/thread?id=4519 Hope this helps. You may want to change the transmission oil also.