When you're offering an add-in through your website you usually have no connection to the people who are using your programming work.
It is not unusual that you have discovered (or been pointed at) bugs in your code or that you've done some updating to the utility you'd like your users to benefit from.
Several microbenchmarks (using Caliper & Yourkit) highlight this release net improvements: Jongo 0.3 is 6 times faster than Jongo 0.2, which make it as fast as the driver!
Have a look at find microbenchmark and save microbenchmark, and at their implementations (find & save).
For various PC problems, we recommend to use this tool.