why some of my items cannot be edited?[Solved]

Hi,
I got a problem and actually it's annoying. I cannot edit some of my flexi created items(no matter what kind). Even their names in Items page are not active and there is no link with them. When I try to open them in the back-end(by writing the url manually), this message will come up that:
"This item is currently edited by another administrator"
And it's not true. There is no other admin.
What's the problem?

Thanks

hello
do this
clean cache
and use global validation for content in joomla tools
regards

Sorry, but I didn't get it.
Could you please explain it a bit more clear and of course with instruction?

Thanks

hello
in joomla menu on top
tools
clean cache
global checking
and try
regards

It worked. Thanks a lot.
So why this happened?

Thanks

to protect an item to double editing joomla protect this but some time if your not deconnected .. this protect
regards
edit you post and add [solved]
thanks