importing plain latex: filename.lyx is from an older version of LyX and the lyx2lyx script failed to convert it.

[Christopher Barrington-Leigh]

I imported a .tex file (containing LaTeX) called myfile.tex and got the following odd error:
myfile.lyx is from an older version of LyX and the lyx2lyx script failed to convert it.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: lyx 2.0.0-1~natty1
ProcVersionSignature: Ubuntu 2.6.38-11.50-generic 2.6.38.8
Uname: Linux 2.6.38-11-generic x86_64
Architecture: amd64
Date: Thu Sep 15 16:30:35 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
ProcEnviron:
 LANGUAGE=en_CA:en
 PATH=(custom, user)
 LANG=en_CA.UTF-8
 SHELL=/bin/bash
SourcePackage: lyx
UpgradeStatus: No upgrade log present (probably fresh install)