[Samba] allocate_print_jobid: failed to allocate a print job for queue lbrmgt

[Mineau, Kevin]

We have recently migrated from a package called Totalnet to Samba to
replace our file and print services.  File services are working great.

>From time to time we get a call that printing stops working.

I have found a post stating that it may be a file space issue.  After
checking, our file systems have plenty of extra space in them and have
never filled up yet.

Our current fix for this is to erase the print queue's tdb file.
   tdbtool /var/locks/samba/printing/lbrmgt.tdb erase

Q1. What sort of side affect are we introducing by erasing the print
queue's tdb file?
Q2. What steps can I perform in order to diagnose or fix the issue
permanently?

Details:
Samba 3.0.20b
OS - AIX 5.1 ML7

Relivant smb.conf settings:
[global]
        printcap name = /etc/printcap
        printing = AIX
        printer admin = root
        load printers = Yes
        print command = lpr -r -h -P'%p' %s

[printers]
        comment = All Printers
        path = /var/spool/samba
        printable = Yes
        printer admin = root, staff
        browseable = Yes
        public = Yes
        writeable = Yes
        read only = Yes

[print$]
        comment = Printer Driver Download Area
        path = /etc/samba/Drivers
        browseable = Yes
        guest ok = Yes
        read only = Yes
        write list = root