Try selecting a thumbnail and click the export button (bottom left)
You can choose all your settings when the export dialog opens. For jpeg quality try a setting between 76 and 100
Thank you, however I've tried this and the same screen comes up..
Try choosing For Email but push up the quality slider and size. Click the Add button to save it as your own hard drive pre-set for future use.
Whether I choose (from drop down menu) the email, hard drive or dvd the right box is still blank, and quality control options are not available.. check out the screen shot I've posted so you can see what I mean!
If LR becomes a bit goofy it’s often worth trashing the prefs.
Start by quitting Lightroom.
Launch Finder and click the Go menu whilst holding down the Option (alt) key. Then go to Library >> Preferences and delete the following file. Note the User Library is hidden by default until the Optn(Alt) key is held pressed.
After deleting the above file re-launch Lightroom.