I suppose this is your problem: You need to use matching versions of UC Control, UC Surface and firmware! There have been quite some changes coming along with UC 1.6 and 1.8, so it is quite probable that some things don't work as normal. You can not use the latest UC 1.8 with older firmware, as UC 1.8 came with a completely new Universal Control. You really need to always do ALL THREE UPDATES, which partly might mean a complete new install. Read the "release notes" and consider the differences between Mac and Windows.
You start from here: Universal Control AI: 1.5.0.36497 | UC Surface Version: 1.5.0.36497 | Firmware: SL 1.0.7784
You should be there: Universal Control 1.8: 1.8.0.38751 | UC Surface: 1.8.0.38751 | Firmware: v9244
Nowadays UC Surface also has Capture integrated (the buttons and the timeline), so you don't need to switch between UC Surface and Capture any longer. For me UC Surface and Capture via Firewire have always been working rock solid. I have always used matching versions of the instances involved.