empty directories need disk space

[basti <black.fledermaus@arcor.de>]

Hello,
on different servers I have cache folders with a lot of small files. Now
all the files are delete but the folder "need" 151 MB.
Whats gonig on here? What is the problem? How can I fix? Delete and
create would be impracticable.

--- /home/somedir/cache/baseall/basecache
---------------------------------------------------
  151.0MiB [##########]
/locks                                                                              

  148.0KiB [          ] /data
  144.0KiB [          ] /config
    0.0  B [          ]  unlimitedTimeout


--- /home/somedir/cache/baseall/basecache/locks
---------------------------------------------
                       
/..                                                                                 

    0.0  B [          ]  cmsproddata-mongo.categoryprodofferlistbase
    0.0  B [          ]  KEEPME

Best Regards,
Basti