Poker Tracker Problem

[Hybrid_11]

Now this might not be related to poker tracker but it's more of a question then a problem. Recently I have been keeping track of my bankroll amount by having my initial bankroll recorded then entering in Poker trackers results on a weekly basis. The results i enter is just money won or lost. What I have been noticing tho is the amount that i get recorded in my excel spreadsheet for the bankroll does not match the actual showing amount when i go to the cashier. It seems to be off by a few dollars lower then what is calculated.
My question is poker tracker reliable for exact win/loss numbers or can they be off by a little. Or what other possibilities out there could be causing this?
The only thing that comes to mind is i know poker tracker has errors so when connection is lost the HH is not recorded and thus scews the results a bit. Is this probably whats going on here?

[highlife]

yeah, its most likely that, or maybe you aren't importing a few hands here or there.