WAL and backup recovery

Hi all:
I've a problem regarding WAL (I think :-)). When recovering
a backup in 7.1.1, the number of files in pg_xlog/ starts to grow,
and eventually exhaust the disk capacity (it ate my 6G partition). I've
the following settings in my postgresql.conf file:

wal_buffers = 4
wal_files = 16
wal_sync_method = fsync
checkpoint_segments = 1
checkpoint_timeout = 30

Right now I'm just testing the new engine, in fact I've installed it
yesterday (yes, I know, 7.1.2 is out today :->), so I don't care so much
about the performance of this settings. But, correct me if I
misunderstood the documentation, whit this config the backend will do a
checkpoint every 30 secs, or after the creation of a new segment
(whichever happens first), and if old segments are deleted why is the
file count growing?
Any help or tip would be greatly appreciated. Since now, thanks a lot.

Yours: Dario Brignardello