Presumably it's the thread the profile is running in that hangs/locks up. Try turning off 'slower comparison' (hashing) and run it again to see if it solves the problem? Though I'm not sure why it should, as it doesn't for us, and no-one else is reporting anything similar. At a guess, Windows on one machine or the other is using up resources doing so (hashing - especially over a network), and falls over very early after starting the copy phase due to a lack of same. Or similar.
In the commercial versions, there's an Invalid Handle error you can get on some installs of Windows trying to do this in parallel (hash both files at once), but the Free version doesn't support that anyway (hence the option to stop doing so on Compare Options is ghosted). But it does indicate there are potential issues with some installs of Windows if you use hashing...
In the commercial versions, there's an Invalid Handle error you can get on some installs of Windows trying to do this in parallel (hash both files at once), but the Free version doesn't support that anyway (hence the option to stop doing so on Compare Options is ghosted). But it does indicate there are potential issues with some installs of Windows if you use hashing...