Description of problem:
When tar 1.15.90 does an incremental backup, it copies too much.  If any file
has been added to (or removed from) a directory, ALL files in that directory are
copied.  Depending on the directory, that could mean way too much data.

Version-Release number of selected component (if applicable):
tar 1.15.90

How reproducible:
Every time

Steps to Reproduce:
1. mkdir t
2. touch t/apa t/bepa
3. tar --create --listed-incremental=t.snap --verbose --file=t.tar t
(This will archive t/, t/apa, and t/bepa as expected.)
4. touch t/cepa
5. tar --create --listed-incremental=t.snap --verbose --file=t.tar t
  
Actual results:
Tar will (re)archive all files in t:

t/
t/apa
t/bepa
t/cepa

Expected results:
Only the new file should be archived:

t/
t/cepa

Additional info:
In the next upstreams version, 1.15.91, this is fixed.  I would suggest an upgrade.

Both FC5 and the latest test relase for FC6, 5.91, has tar 1.15.90.