Found this trying to test the fuerte .rosinstall...

For the file:
https://code.ros.org/svn/release/download/stacks/geometry/geometry-1.8.0/geometry-1.8.0.tar.bz2

The following fails:
tar -xf filename

but the following succeeds:
tar -xjf filename

no problem with the other archives
---
rosinstall --version
rosinstall 0.6.12
vcstools: 0.1.10
SVN: svn, version 1.7.4 (r1295709);
Mercurial: Mercurial Distributed SCM (version 2.1.1);
Git: 1.7.9.5; 'reset --keep': True, submodules: True
Tar: (GNU tar) 1.26;
Bzr: Bazaar (bzr) 2.5.0;

tar version 1.26

error message <<===
tar: Archive contains `\266k$\215\201=s\326\321-\343\336' where numeric 
off_t value expected
tar: Archive contains `\367m\331݀\350\035F' where numeric mode_t value 
expected
tar: Archive contains `ob\347nz)\336\367\\=\a\276' where numeric time_t 
value expected
tar: Archive contains `\306C\256\262J\201l\t' where numeric uid_t value 
expected
tar: Archive contains `\260\206\347*\322\301\265`' where numeric gid_t 
value expected
tar: BZh91AY&SY0_�W�����������������������������������������Ϸn8����D�

K
*T�Ͻ��CF����;��p���u�Xt��l: implausibly old time stamp 1970-01-01 
00:59:59
tar: Skipping to next header
tar: Exiting with failure status due to previous errors
===