All files from http://www.idris.fr/bug/beta.tar are not well extracted in linux compare to aix or irix tar. The Bernard.Pichon.20Juin96-f2000-propositions-francaises.ps.gz file is extract to the current directory on linux but is extract on htdocs/su/Nouveautes/seminaires/annee_9596/ elsewhere !
There are two similarly named files in your beta.tar file.
Woops, solaris /bin/tar verifies a real problem here.
Fixed (by upgrading) in tar-1.12-10.64011. Thanks for the test case.
QA testing for tar-1.13.11-1.i386.rpm: (lorax) Correct behavior shown for this test case: # tar xf beta.tar # find . -name Bernard.Pichon.20Juin96-f2000-propositions-francaises.ps.gz ./htdocs/su/Nouveautes/seminaires/annee_9596/Bernard.Pichon.20Juin96-f2000-propositions-francaises.ps.gz