Lens cover stuck open

I recently had the lens cover stick partly open.  There are 4 segments to the lens cover, and if we number them from the top, number 2 was not closing.
I gently flicked the segments a few times, in case there was a grain of dirt causing it to stick (although the camera has never been in a dirty or dusty environment).  This caused the lens cover to close fully each time, but now it would not open fully, segment 1 would not open, although it would stay open if moved by finger.
Anyway, after a bit of fiddling, I got it working properly again.  The way that the lens cover appears to work is that only segments 2 and 3 are pushed open or shut by springs, segments 1 and 4 are pushed open and shut by tiny tabs that catch on segments 2 and 3.  If the segments somehow get pushed out of alignment, then they either bind (causing the cover not to shut), or they get disconnected (causing the cover not to open fully.
Now I am not sure exactly what I did to get the mechanism form the stuck open state to the not opening state, but from there the way to fix it is to:
-With the lens open...
- Hold segment 2 in the closed position with firm finger pressure (which will tend to push it towards the lens).
- Push segment 1 towards the open position until you can see that it has cleared the edge of segment 2.
- Lift segment 2 way from the lens so that it will rub past segment 1 as you...
- Move segment 1 to the open position.
- Repeat if necessary to get the technique right.

I can't provide any guarantees, and I am not about to repeat the excercise on my camera, but it was a lot easier than sending it off for repair.

V12mike--you rock! this did indeed fix my stuck lens cover.  to add on to your solution, i had the top half of the cover stuck shut and the bottom half stuck open.  to get the bottom half to the shut position, i covered the lens with a little piece of paper and then used tweezers (VERY gently) to ease out the inner segment (segment 2 i think by your account), and held it in place as i reset segment 1.  this did the trick!  
appreciate your help immensely....cheers!

I have a panasonic lumix that wouldn't open or close properly after I had it in my pocket and had lost the case. I tried the above with no results. I was able to fix it by putting my nail into the side of the casing (the part that is still grey with lens open-same color as lens) and gently prying it outwards to create more space. There is a groovebetween the glass and the casing and that is what I put my nail in. Hope this helps someone!

Thanks helpfuldave, same problem and solved it easing metal/plastic with finger nail outwards gently i.e. where front of protective shutter rubs against - the grey rectangular part.

V12Mike is to be thanked again, for bringing hope to a hopeless looking situation. I had a student's ZS5 with the cover 2 jammed. It looked bent, as if something had impacted it from the front. That might be, but it was actually not damaged, apparently, and was able to spring back. Following V12Mike's general procedure and numbering of the cover blades, I:
1. Powered on, to open up the lens. (cover 2 appears bent inward slightly.
2. Reaching from the top of the lens, and the back of the camera, used my right index fingernail to gently pry blade up, away from the lens glass.
3. There was a snap, and the whole cover assembly popped into place (fully open), as it should. No blades appear now to be bent or out of track, and they work perfectly.

Zs19k. Top lens cover opened/closed fine. Bottom lens cover remained retracted when camera turned off. i inserted very this edged tweezers end into small groove to widen it temporarily a couple of times and the lens cover popped out to it's normal closed position. Not sure if gently prying the groove dislodged a speck of dust or whatever. It works now!

The top half of the lens cover on my DMC-Z5S was always stuck open, it never actually closed after the first time I powered it up. After reading the other suggestions on here I finally figured out that the very inside flap of the top half was bent a tiny bit. So I grabbed my tweezers, love those things, and bent it in the opposite direction and it now works perfectly. This is the 2nd Lumix I've had and both has had this problem. They also have the problem of getting dust on the sensor

Thanks all, and thanks especially to V12Mike and Tom Diaz. I did exactly what Tom suggested, and with two minutes of effort successfully fixed my wife's Panasonic Lumix DMC-SZ7, which had had its lens barrier stuck in the closed position for a month after she dropped it. I heard that same satisfying "snap" when the stuck blade flicked back into its proper position. A spritz of lens cleaner and she was back in business. Thanks so much!
Note: I used a pair of SOFT PLASTIC pliers from one of my daughter's games when my fingernail proved insufficient for the task.

My 2 lens got stuck at lens 1 ( the bottom and largest lens) It fell on the ground with the shutter lens hitting the ground first.