Uh oh - procmail forcing lock?

I'm thinking this means that I had my cache set too low, and it barfed?

I had about 300 messages stuck in limbo, making my hard drive spin like 
mad. I was forced to kill all 300-odd instances of procmail 
running....Where'd all the messages go?
This is all I have relating to the cache in my .procmailrc file...

DUPFILE=$BACKUP/dups
CACHEFILE=$BACKUP/.cache
CACHESIZE=500000
GARBAGE=/dev/null


# BEGIN RECIPES

:0 cW: $CACHEFILE.lock
| formail -D $CACHESIZE $CACHEFILE

:0 a:
$DUPFILE

-----
begin wierd log

procmail: Forcing lock on "/export/home/twabuse/Mail_Backup/.cache.lock"
procmail: Forcing lock on "/export/home/twabuse/Mail_Backup/.cache.lock"
procmail: Forcing lock on "/export/home/twabuse/Mail_Backup/.cache.lock"
procmail: Forcing lock on "/export/home/twabuse/Mail_Backup/.cache.lock"
procmail: Forcing lock on "/export/home/twabuse/Mail_Backup/.cache.lock"
 From postmaster(_at_)ne(_dot_)mediaone(_dot_)net  Mon Nov  1 04:37:46 1999
 Subject: Your Mail box has exceeded the Size Limit
  Folder: 
/dev/null                                                        1595
procmail: Forcing lock on "/export/home/twabuse/Mail_Backup/.cache.lock"
 From postmaster(_at_)ne(_dot_)mediaone(_dot_)net  Mon Nov  1 04:50:08 1999
 Subject: Your Mail box has exceeded the Size Limit
  Folder: 
/dev/null                                                        1585
 From postmaster(_at_)ne(_dot_)mediaone(_dot_)net  Mon Nov  1 08:47:27 1999
 Subject: Your Mail box has exceeded the Size Limit
  Folder: 
/dev/null                                                        1589
procmail: Forcing lock on "/export/home/twabuse/Mail_Backup/.cache.lock"
procmail: Terminating prematurely whilst waiting for lockfile 
"/export/home/twabuse/Mail_Backup/.cache.lock"
 From peter(_at_)unica(_dot_)co(_dot_)uk  Mon Nov  1 05:29:23 1999
 Subject: Fw: Porn Star Houston *SNIP* 600 guys!!!
  Folder: 
**Requeued**                                                        0
procmail: Terminating prematurely whilst waiting for lockfile 
"/export/home/twabuse/Mail_Backup/.cache.lock"
*snip lots of the same crap*
   W. Mark Herrick, Jr. <markh(_at_)va(_dot_)rr(_dot_)com>          _.._        
_.._
       Senior Security Administrator             ,','"_:./\/\,'_ `.`.
       Team Lead - Usenet Operations            /_:--:_ ( oo ) _:--:_\
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