Ok so repeated entries like you have are an indication that the download and install has not succeded.
To check go to About This Mac click System Report the Software and then Installations. If you do not
see the iMovie 10.1.1 update listed, it has not installed.
One thing you could try is this.
Above is the path to the folder that needs to be removed.
The folder is normally hidden, so you may not see it.
In Finder use the Go To Folder item under Go and type in /private/var/folders in the text box
and from there navigate to zz and then the folder zyxvp........ ending in 68, control-click and then Move To Trash, don't delete
you could also drag it to the desktop before for extra safety.
Restart the Mac and relaunch the App Store and see if you are able to download now. The folder and files within it are regenerated on Restart.
If you are happy you can then empty the Trash and delete the one on the desktop if you did that.