Just another quick comment on the new LP foil tips, now that I've been using them for a couple of months. They have a tendency to go off target occasionally for no apparent reason. I would guess it's because dirt is breaking the connection between the grub screws and the tip. Twisting the tip always fixes it on the strip. Does anyone have any advice on avoiding this problem? (Besides cleaning out the tip every couple of weeks).

The tips are great in every other respect - travel is German-standard, the barrel is dent free and the screws are fine. In particular, the new hardened screws have hardly worn at all where they meet the tip.