rounding in v.spag or G_get_site()?

I read a sites list (in the "num|num|#cat desc" form) with G_get_site and
write them as vector attributes. I noticed a rounding problem when a site is
near a border.

My region is the unit square in an xy coordinate system. When a site
as the coordinate (0.997171,something), the problem is noticed.
Once the vector map is labeled, I then run v.spag, which says that
I have a point-to-area failure for (1.00,something-rounded).

Has anyone else noticed this?

--Darrell