There appears to be an incompatibility between Synapse and Vista in that using the Skype dial icon in Synapse will cause a crash. This is being investigated ...
I just checked on Windows 2000 .. dialing works fine. The Skype4COM.dll has to be registered .. that should happen normally though with the Skype install. And Skype has to specifically allow Synapse to use Skype functions.
I just tried on XP Pro, and the Skype icon does dial the number okay. So, it just appears to be a vista problem so far.
I've now got Synapse to dial out to Skype again ... but this time under Vista. But, unlike the earlier versions, you have to make sure your Skype status is set to online .. whereas before Synapse was able to set this for you. If Synapse attempts to set the status, we get an error under Vista.
Skype must have fixed something because I can now send SMS messages from Synapse using Skype under Vista.