textarea with 'cols' specified doesn't work well

Binary package hint: firefox-3.0

html source:
<textarea id="id_content" rows="10" cols="40" name="content"></textarea>

when i keep pressing a key such as 'a' key,then it doesn't auto break line and show the horizontal scroll bar.

ProblemType: Bug
Architecture: i386
DistroRelease: Ubuntu 8.10
Package: firefox-3.0 3.0.6+nobinonly-0ubuntu0.8.10.1
ProcEnviron:
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 LANG=zh_CN.UTF-8
 SHELL=/bin/bash
SourcePackage: firefox-3.0
Uname: Linux 2.6.27-11-generic i686
UnreportableReason: 这不是真实的Ubuntu包