[tex-k] disappearing inserts

[David Guichard]

Hi--

On a new ubuntu installation, I noticed that some midinserts are
disappearing into the ether on me; I'm using texlive 2009-13 on ubuntu
11.10. The same code works perfectly on my 10.04 machine with
2009-7. I have a "figure" macro that uses midinsert; I changed the
midinsert to a topinsert, and *every* figure disappeared, and indeed
the midinserts that disappear are the ones that are converted to
topinserts.

All non-standard macro packages are the same on the two machines, and
the plain.tex files are identical. I even tried copying the tex
executable from the good system to the problem system, and the problem
persists. 

This is very mysterious to me--where else could such a problem be?

Thanks,
David