[pdftex] Problem with hlines in pdftex

[Gregory Collins]

Hi,

I am having a problem with the .pdf files being generated by
pdflatex. I am using the longtable package to make documents with
tables having rules in them. When viewing the resulting .pdf files in
Acrobat Reader, I'm seeing what look like rounding errors: the
vertical and horizontal rules in the tables appear and disappear at
random, and sometimes lines end up being wider on-screen than others.

I (obviously) would like these lines to be at least a pixel wide even
when the document is zoomed-out. Changing the anti-aliasing settings
in Acrobat Reader doesn't help. Is there anything that I can do to
make this problem go away?

Gregory Collins
greg at subrosa.ca