"Degrading" TABLE column

[Duncan Hothersall <dh@capdm.com>]

I'm trying to solve a problem with a TABLE in a large-ish (600 page)
book. The table occurs in an appendix, and the contents of one column
are spilling out into the next column on the right.

The weird thing is that when I process just that bit of the book, the
effect is much smaller, and when I process the whole book (with the
table near the end), the contents move all the way to the other side of
the next column, moving almost a full column's width to the right.

I will try to work up an example, but in the meantime, does this ring a
bell with anyone in terms of something (an offset value, and alignment
parameter?) which "degrades" over the course of a large run, such that
the effect is minimal in a small document, but visible at the end of a
large one?

Thanks,

Duncan