TrekJapan,
you might want to drop by the Dahon forums for Dahon specific issues, tips, etc.
http://www.dahon.com/forum/
Just an FYI, although the P8 is great, there has been some concerns regarding its seat post sliding, and some other issues with the hinge, and handle post.
which... personally i've not seen, but perhaps because i'm riding a high end model vs. the mid range models which are the ones that always complain about those problems.
The truth is, it all comes down to maintenance, keeping it maintained, it will keep it from developing any of the above described problems.