I had this problem with LR5 and each upgrade through LR5.2. I'm running Windows 7-64 bit on a 1st generation I-7 processor.
I put a CF card into my Sandisk ImageMate reader, which then is viewable using the Computer dialogue. I then open LR, wait for it to read the catalogue and render the images. I then go to Import Photos and Video, name the subfolder into which I want the pictures copied, and specify some key words. The images get previewed and I click on Import.
The progress bar appears in the upper left corner of the screen but I wait and nothing happens. I have to close LR, reopen it, and go through the same process (except that the new folder's name is retained). this time it works like a charm. Again, this problem has been there since LR 5.0. Any thoughts on what might be causing it?