I can't fill in form within TB

[mi]

Binary package hint: thunderbird

I use "ThunderBrowse" to open web pages within Thunderbird.
But when I try to fill in form, for exemple to sign a petition, it does not work !
In the name place I can only type 2 digits ( c and h for chaplin and the rest (here "aplin") goes at the bottom of the page within "move message to") ; for first name 3 digits are accepted ; no problem with "job and town of residence ; but with "address mail" only two digits are accepted again.

ProblemType: Bug
Architecture: i386
Dependencies:

DistroRelease: Ubuntu 9.04
NonfreeKernelModules: nvidia
Package: mozilla-thunderbird None [modified: /var/lib/dpkg/info/mozilla-thunderbird.list]
PackageArchitecture: all
ProcEnviron:
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: thunderbird
Uname: Linux 2.6.28-15-generic i686
UnreportableReason: Ceci n'est pas un authentique paquet Ubuntu