There was a bug that was added in 2.1.6 that caused the program to crash in certain situations, but it only affected a small number of users. If version 2.1.6 is working fine for you, then you can continue to use it.
If you're experiencing stability problems with version 2.1.6, you can either revert to version 2.1.5 or you can try the new test version (version 2.1.
which has a fix for the problem, but is still in testing. Version 2.1.8 is available here:
http://skjm.com/icam/iCamSetup2.1.8.exe