Yeah, everyone gets mixed up about this one - possibly the people who mainly buy New Order's albums rather than singles.
Technique came out in early 1989 with the original, New Order-produced 'Round & Round'. That version was then remixed to make those "club" mixes on that cutesy 3 inch Remix CD single. The actual 7 and twelve inch mixes were re-recorded with Stephen Hague, not long after Technique came out, hence the extra harmonies and different arrangement.
That, re-recorded seven inch mix was then remastered with a little tweaking for 'The Best Of' in 1994. The only really noticable difference is the wide stereo panning of the opening orchestra hits, and the lack of delays on Barney's voice in the verse ("Done to me, done to me, done to me", etc.)
I think many people think 'Round & Round 94' was a brand new mix made for the best of, if they've never heard the 1989 single version. My favourite is the 12 Inch extended Stephen Hague version, for that nice long instrumental build-up, but the Technique version sounds less dated when you hear it now.
There's also a nippy little "Edit" on some American CD promos of the original album version that would've made a nice single version to!
Mr Discography clears things up, once more.
Andy.