I believe it is a common problem but there is no way to tell if/when it starts to dislodge. It all depends on how often you insert/remove the iPad. Mine has stayed on, though it has moved a bit out of place in a couple of spots. I just pushed the strip back into place in those spots. I've found that inserting the iPad at an angle (face lowered toward the keyboard) then standing it up and reversing procedure helps.
I had this happen on all three Ultrathins. I agree with mtnmedic that you should insert the iPad tilted forward, then tilt it back. I believe that the problem with the strip rising up happens when you insert the iPad in portrait mode.
I've been pushing the strip back down, or when it gets really bad, pulling it away from the channel then sticking it back on. With one of the keyboards, I let it go and it got so bad it damaged my InisibleShield and I had to replace it.
Btw, after the second one I called Logitech Customer Service. They are always very helpful. They replaced the keyboard right away. With the third keyboard, I am trying to limit using it in landscape mode, although I still have to push the strip down from time to time.
I did have that problem, and my solution was to peel the strip all the way off and use some nail polish remover on a q-tip to get all of the sticky off. Then I took a strip of electrical tape, cut it down the length to the width of the gap, and stuck that in there. It works pretty well, just make sure you get all of the sticky stuff out.
It is apparently very common. I tried scrubbing it away with alcohol however I had little success. What I ended up doing was placing a piece of scotch tape over the length of the stick strip and then cutting the half of the tape, that was not covering anything, off. I imagine you would be able to find the same type of tape at an office supply store and simply replace the strip as well, though this may also involve cutting it down to size.
I don't know. However, make sure you register your items on Logitech's website. If it does come off they will send you another one free. I had a problem with my remote which got a cracked screen. I couldn't figure out how it got there since I hadn't drop it or an animal chewed on it. I was asked by Logitech to send a pic which I did. The person who viewed it said they could not do anything for me. I hung up and called again and then asked for a supervisor and they reviewed the pic and approved me for a new one. It was shipped out the next day and I didn't have to ship my broken one back to them. Had they not did that I would have not rated or recommended Logitech as a good company to deal with. I'm not sure if that is how they handle problem complaints for their products or not. Since I spent nearly $200 for that remote I wasn't going to let them dismiss me over this issue.
I was also worried about that problem since so many people mentioned it but I was SO happy to see that the keyboard we ordered in Oct 2012 actually does not have some kind of white foam strip struck on by adhesive but instead is a hard, white plastic shell that fits inside and lines the entire inside of the groove so there is no way that thing is going to slowly get loose and get adhesive everywhere. The only explanation I can think of is that Logitech recognized this design/manufacturing error from all the customer complaints and redesigned the groove with this new "liner?" We love this keyboard, SOOO feather light and awesome to type one. Seriously, it's like a mini MacBook Air....
I haven't experienced this problem. Like some of the others, I tend to insert the iPad at an angle. BTW: I have the iPad 2 - not sure if the problem varies depending on which version of the iPad you're using.