JPY Currency Error

I am from Japan.
There is an error in paypal payment in Japanese Currecy in yen.

settings in WP
http://raku27.net/error_member/001.jpg

1 JPY = OK
10 JPY = OK
100 JPY = OK
1000 JPY, the number returns to 1 in Paypal page.
http://raku27.net/error_member/002.jpg

Are there any resrictions when more than 1000 in price setting?