Actually you probably do need the 1.2 update even on FS2_Open. There are definitely differences between the root_fs2.vp file in 1.0 and 1.2 and I'm not 100% certain what gets updated.
From the patch's readme file:
1.20
- Glide texture stretching fix
- Standalone server CD checking fix
- Jump Node placement in Fred2
- Pilot's score added to multiplayer debriefing
- Technical database does not show duplicates of each weapon
- Intro movie no longer shows up twice in cutscene player after campaign
- Objectives in Templar campaign assigned points
- Wingmen now receive a score bonus when large ships are destroyed
- Mission 3-4 conversation added
- Templar 3 mission objective text altered
- M-02 debriefing /Return to base issues fixed
- Mission 3-7 messages changed to accurately reflect mission occurrences
- Loop 2-1 directives issue resolved
- Mission 1-4 failure debriefing added
- Loop 1-2 message timing optimized
- Loop 2-2 directives cleaned up
- Agrippa persona fixed in mission 3-5
- Loop 1-3 mission outcome for blowing up civilians fixed
- Loop 1-3 in mission messaging fixed
- Mission 1-8 briefing icons fixed
- Mission 1-9 debriefing typos fixed
- Mission 1-5 Discovery/Trinity personas fixed
- Training 5 directives cleared up
- Mission 3-1 message timing optimized
- Mission 3-6 directives corrected
- Mission 3-8 briefing icons corrected
- Mission 3-9 alternate names removed from ships
- Mission 3-9 weapons loadout fixed
- Cyclops bomb names fixed
- Mission 2-7 directives fixed