sqwebmail-ip suddenly owned by root

i've got more and more user complaining about this
following error when they try to login : 

Internal error (module sqconfig.c, line 63) - contact
system administrator

i've found out that the error is caused by
sqwebmail-ip file suddenly owned by root.root. i just
manually chown it back to vpopmail.vchkpw and the
problem solved. i also notice that not every user has
this file in their Maildir directory. why? 
somebody in sqwebmail list once told me that this
could be a bug. is it true? has it been fixed in the
latest sqwebmail? 

regards,
gregor

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