Old Harmony Uke with touchy Friction Tuners

I recently purchased an old Harmony uke with friction type tuners. The tuners fit nice and tight but my problem is that the slightest movement (either tightening or loosening) of the tuners and the string goes wildly out of tune. Is this common with ukulele's or is this something unique to friction tuners? Much thanks in advance for any help you can give a newbie!

Like Nylon string classic's, uke strings are slippery beasts. Make sure you lock down that string to itself, pass it through the hole twice if there's room. It's the initial loop that holds it, then as it wraps it goes to pitch. Good luck and continue twangin...flailing? What would you call it?

At the outer end of each of the tuning keys there is a small screw. Tighten that - not too tight - but pretty snug and that should help.

Also check to see if any of the other small screws and bolts are tight.