Each version of DicomObjects can come in several "Sub-Versions" denoted by the last digit of the version string, and these are as follows:
.0 : This is a time-limited, trial copy (as used for free initial downloads). Your license file (if you have one) will not work with this copy!
.2 : This is a standard release version for normal developer use
.5 : This is also a standard developer release, but with inclusion of the DirectShow enhancements
1, .3 & .4 : These are special purpose custom-builds......if you need one of these, then you will know about it already!