Hi Lynn,
This definitely sounds like some video subsystem issue. What video card do you have? (Hope not some Intel integrated chipset...)
To test this out, go to your Window menu in SU > Preferences > OpenGL settings and disable hardware acceleration. If this "seems" to help, you should either update your video driver or if you do not have a decent, fully OpanGL compliant card, get one.
In older SU versions, there was a "Correct reverse picking driver bug" option there, two, which couldbe good for your second issue but that was for some old (nowadays rare) video cards.