2nd table row border rendering problem when hovering

[Uqbar]

Binary package hint: firefox-3.0

THE PROBLEM.
The second <TR> of a table with "border-collapse:collapse;" style and whose <TD> have a ":hover" style defined,
shows incorrect borders during hovering.
In particular, the second <TR> borders disappear when hovering from 2nd to 1st <TR>.
Any other movement is ok, even from 2nd to 3rd and from 1st to 2nd.
A couple of screen shots will follow.

EXPECTED BEHAVIOUR.
All border to be correctly displayed during any hovering.

HOW TO REPRODUCE.
Load the provided HTML file and hover with the pointer from any cell in the 2nd <TR> to the 1st <TR>.

ProblemType: Bug
Architecture: amd64
DistroRelease: Ubuntu 8.10
NonfreeKernelModules: nvidia
Package: firefox-3.0 3.0.8+nobinonly-0ubuntu0.8.10.2
ProcEnviron:
 SHELL=/bin/bash
 PATH=/home/username/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 LC_COLLATE=C
 LANG=en_US.UTF-8
SourcePackage: firefox-3.0
Uname: Linux 2.6.27-14-generic x86_64

[Uqbar (uqbar)]

This is the table displayed before hovering the pointer.

[Uqbar (uqbar)]

This is the table displayed after hovering the pointer.