Qmail and procmail: How to get rid of "_Couldn't_Create_" ?

Procmail seems to want to do something in /var/spool/mail.  But since I use
qmail, I don't have a /var/spool/mail.  Is there a way to have procmail not try 
to create temp stuff there?  This log message really bugs me.

Log excerpt:

879268536.097156 starting delivery 273: msg 88172 to local 
dave-mlist(_at_)wave(_dot_)bfnet(_dot_)com
879268536.432330 delivery 273: success: 
procmail:_Couldn't_create_"/var/spool/mail/dave"/did_0+0+1/

Dave