After importing some older catalogs and files from a previous HDD, Lr is becoming unresponsive every time I do more than open it. Scanned everything before moving. Running Win7 64, 8 gig RAM on and Intel DP67BG and an AMD R9 270x. Everything updated.Lr lives on a SSD, files on fairly new and fast HDD.
Make sure your graphics card drivers should be updated. Here is the link to install the most recent update : http://support.amd.com/en-us/kb-articles/Pages/latest-catalyst-windows-beta.aspx
Restart machine after that and then, try to work in Lightroom.