hmm we did check that the fixltx2e change didn't break float's H if the
packages are
loaded in the expected order (fixltx2e first). I'm not sure it can
really do anything sensible
if loaded after other packages have redefined latex internals.
Even if it detected the situation there's not much it could do other
than not
make the definition. In general I'd say it can't detect arbitrary
packages making arbitrary
changes although in this case, perhaps it could make an exception as the
main error
case it is detecting is using [H] without loading float (which
previously took the float
to the end of document with no warning) although probably a better fix
would be for
float to delay its definition to begin document
David