turns out the colored faceplate was binding against the stem of the rotary button. it seems the hole was mis-placed (just slightly but this was enough to make the knob rub).

One thing that i noticed was that the hole in the faceplace cut for the rotary button leaves very little room for errors of this nature... it is cut with almost no extra space around the stem of the knob.

I took a dremmel rotary tool with a very wide attachment and just center-bored the hole to give about an extra 1/8" of space in the radius of the opening. That worked perfectly.

The button no longer sticks in any fashion. Thanks for all the good advice, people!

- Dixieland
MK1 : 6 GB : s/n 00246
MK2 : 16 GB : s/n 080000348