brucemeacbook,
Since 2009, there have been several updates, including two new OS releases. Sometimes, some settings files are kept along due to specifics and some particular options might mess up with your network or bluetooth.
That is why, even with iPhones and iPads, people say to "reset network settings", which could also be done on a Mac.
Please be careful with these steps, you're dealing with settings files, and if you mess up, you might need to go single user in boot mode.
First, you could try to reset your bluetooth settings.
1 - Open Finder
2 - Create a backup folder, lets say in your desktop named "MyOldBTPreferences"
3 - Menu "Go" --> "Go to Folder..." then type "~/Library/Preferences"
4 - Search for "bluetooth"
5 - Move those files out of that folder to your "MyOldBTPreferences" folder
Now, lets get rid of the bluetooth System Preferences files
1 - Open Finder
2 - Create a backup folder, lets say in your desktop named "MyOldBTSysPreferences"
3 - Menu "Go" --> "Go to Folder..." then type "/Library/Preferences"
4 - Search for "bluetooth"
5 - Move those files out of that folder to your "MyOldBTSysPreferences" folder
Please do note that the "~" in the first step makes all the difference in the world, be careful.
Finally, restart your Mac, see if that works for you.
Also, some say that even network options might affect the bluetooth operation. I've never come across this situation, but if you ever want to "reset network settings" on your Mac, here are the steps to it:
1 - Open Finder
2 - Menu "Go" --> "Go to Folder..." then type "/Library/Preferences/"
3 - Find the "SystemConfiguration" folder
4 - Rename that folder to lets say "SystemConfiguration.old" or whatever else you want to, as long as you rename it
5 - Restart your Mac
This should reset all network settings, and get rid of older files and stuff you may not need anymore. It is always a good idea to keep the old folder as a backup in case something stops working and then you can just restore it.
Again, please be careful with these operations, and if you're comfortable executing them, let us know if it works for you.