Are you applying a develop pre-set when you import? Could that be the cause of the stop darker?
If so try tweaking the settings and save a new pre-set.
Otherwise you can make relative adjustments to a batch of selected images in the Library using Quick Develop. Try clicking the button for one third stop a couple or three times.
Thanks for the suggestion.
I have tried adjusting in the library module but then it makes the image too bright. The problem is that Lightroom is displaying the image too dark, not that the image is too dark to begin with. When I export the image (which looks too dark) and view in paint or upload to my site, the image looks correct. Its just too dark in Lightroom. This is mind boggling to me. The only way I can see it correctly in Lightroom is to have Use GPU checked but that is when I get constant crashes.
To prevent Lightroom to crash you may install Previous version of your graphics card.
Open Device manager
Expand Display Adaptors
Right click on your Graphics card
Click Update Driver Software
Browse for Driver Software
Let me pick from a list of Device Drivers
Install a Previous version of Graphics Driver
Lightroom GPU FAQ:-
I've tried every version since April 2014. I think there are about 5 of them now.
Here's another mind boggler.
I borrowed an ASUS GTX 970 STRIX, installed it, loaded the drivers and Lightroom works fine (first time I've seen it work properly.) Removed card, put the R9 290 back in and Lightroom still worked fine after startup. I rebooted and then it wouldn't work again and still won't. I really want to keep the R9 but the GTX is looking better and better.