Please reset the Lightroom Preferences.
Mac OS: /Users/[user name]/Library/Preferences/com.adobe.Lightroom3.plist
Windows 7, 8: C:\Users\[user name]\AppData\Roaming\Adobe\Lightroom\Preference\Lightroom 3 Preferences.agprefs
Rename the Preferences file to Lightroom 3 Preferences.agprefs.old Or com.adobe.Lightroom3.plist.old
Open Lightroom try importing the files again from the source, also check if you can see the source listed in Finder/Explorer.
Let us know if that helps.
You need to reset the Lightroom Preferences
Go to Location: /Users/[user name]/Library/Preferences
Look for the Preference file: com.adobe.Lightroom3.plist
Rename it to "com.adobe.Lightroom3.plist.old"
then open Lightroom and start using it.
I was finally able to do this and it did not fix the problem.. i still can not see my phone or camera as a source.