In CC:E the activated units do highlight as normal. Am I doing something wrong, or is it just the Vassal version that I am using?
This was also an issue in CC:E v2.2 prior to the current release (v2.3) released earlier this month. Tim most likely has to rebuild the CC:P module to account for some coding changes in Vassal since Vassal 3.2.3. The solution is to play CC:P using Vassal 3.2.2 until the tweaks can be applied.
Details can be found here:
Vassal 3.2.5 issue: no activation
Vassal Module Updated to 2.3