DNB usually stands for Do Not Bill.  It allows time or expenses slips to be tracked and reported on, but never shown or billed to the client.

It is possible for a slip in newer versions to be partially DNB and partially billable.  

I think what you are seeing is an attempt to show you on the prebill if you have any DNB, as by definition, it will not show up on an actual bill and might be missed.

Nancy Duhon, Esq.
Duhon Technology Solutions, LLC
Master Certified Consultant for Sage Timeslips
Providing individual Consultations and Third Party Remote Desktop Support - including older/unsupported versions.
404-325-9779
[email protected]

In some cases, the rounding for slips based on the time entry may be showing a partial amount as DNB.  For instance, 3.10 hours at $360.00 an hour should end up being $1,116.00.  But if the slip is entered as 3h 6m 22s, it will have the 22 seconds portion shown as DNB.

And the precision on the client can be at issue as well, where some clients are calculating one-third as 0.33 and not the more precise 0.3333.  You can find this setting on each client in Client Info under their Charges tab, and is listed as 'Time spent calculation method'.