Hi Ev, I'll give a brief description about the way this by-user tracking method works as a background to some different possibilities.  By user tracking in HP WJA relies upon SNMP traps bound for the WJA service from the printer when a job has released.  WJA receives the trap and interogates the printer using several queries after each and every job it receives a trap for.  The trap is only sent once from the printer and not all devices support traps (for example, while the HP LaserJet M3035 mfp offers support for this feature, other more consumer oriented devices may not like lower end all in ones).   If you're missing data from a larger collection, one possibility may simply be lower end devices not having the capability.  There are other possibilities like UDP traffic (SNMP) being dropped across routers under stress or even something as simple as a device having been reset which needs to be reconfigured with the appropriate trap.  There could be different considerations, so I'd highly recommend you call into your support resource and figure out where to go from there.  I always like to remind customers that this is a handy feature, but if you're using it for rigorous job accounting for billback, auditing or quota control, a job accounting package to compliment HP Web Jetadmin may be the better of the options.  HP works with several partners including Capella, SafeCom, Ringdale, Equitrac, Pharos, etc who have advanced in-printer options as well.  Your HP sales representative can help you with sales options there as we resell and support many directly.  Take care, B.