Why no JTAG connection?
Altera tools are finicky sometimes. I've had issues with them similar to what you describe.
What I do when it gets to this point is do to device driver and uninstall whatever driver is there. If needed, display hidden devices. Then reattach the device and reinstall the drivers that come in the Quartus II 13 directory.

By the way, its best for you to stop using Quartus II 10 if possible. I say that because Altera only supports up to 3 versions back. Version 10 is already outdated and won't be supported by them. There are plenty of fixes in the new versions (and sometimes some new issues) and some versions are really bad about device support.