On the ground, stock engineer assembly works fine (I built a little beacon with the Stamp-O-Tron on the Mun with no problem). In orbit, I can attach parts just fine. But when I enter construction mode, do my work, and leave construction mode, I notice that my orbital parameters have changed. This is aggravated when I have my engineer try to return to the ship, causing premature deorbits. In addition, the engineer can't move much relative to the ship.
Why does this happen? Are there workarounds or solutions? (KAS/KIS doesn't have this problem, but it doesn't allow adding struts in-flight.)