I previously wrote that:
The next step is to produce patches against the X server 1.4 in Debian/Sid and Ubuntu/Hardy, and then get the fix merged into the upstream X.org tree before X server 1.5 is released.
Good news: Bryce Harrington produced patched X server 1.4 packages for Ubuntu/Hardy!
The LTSP and OLPC communities are hereby invited to test this ASAP. If nothing major is reported, this will be become the standard X server 1.4 for the Ubuntu/Hardy LTS release, following which the patch will also be merged into Debian/Sid.