firefox 3.5.3 does not HTML import bookmark tags from firefox 3.0.14 bookmarks library

Binary package hint: firefox-3.5

'~$ uname -a; Linux T43 2.6.31-14-generic #48-Ubuntu SMP Fri Oct 16 14:04:26 UTC 2009 i686 GNU/Linux'
I used an USB pendrive to transfer my bookmarks from firefox 3.0.14 to firefox 3.5.3 on another computer.
On the firefox 3.5.3 I have now these bookmarks but without tags.
I expected that the HTML export and import would copy the bookmark tags as well.

ProblemType: Bug
Architecture: i386
Date: Tue Oct 27 15:33:50 2009
DistroRelease: Ubuntu 9.10
Package: firefox 3.5.3+build1+nobinonly-0ubuntu6
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
SourcePackage: firefox-3.5
Uname: Linux 2.6.31-14-generic i686