This appears to be related to LyX Trac Bug #6680, and occurs due to an incompatibility with LyX 1.6.5 (currently available from the Lucid package repositories) and Qt 4.6. This issue has been repaired in LyX 1.6.6 and greater. For Meercat, Ubuntu should consider syncing the LyX package with the Debian testing. See Launchpad bug #618690.
This appears to be related to LyX Trac Bug #6680, and occurs due to an incompatibility with LyX 1.6.5 (currently available from the Lucid package repositories) and Qt 4.6. This issue has been repaired in LyX 1.6.6 and greater. For Meercat, Ubuntu should consider syncing the LyX package with the Debian testing. See Launchpad bug #618690.