Its pretty simple actually...
Our build numbers are a counter. Every time we release anything it gets a new number and the counter goes up.
in this case...
306 was the last public AHP release.
307 was some bug fixes to some European software based on the reseller's feedback.
308 was some more minor changes to the same software based on a second round of feedback.
309 was an evaluation release of some software to a reseller.
310 was the next number in line when we were ready to release AHP again.
We use this numbering system since a lot of our products contain shared components. This way, for example, you will always know if the x10net.dll from AHP or from Vanguard ICC is the more up to date one.