Dinovo Logitech wireless keyboard problems

Hi, I just recently purchased a dinovo wireless keyboard for mac. i am having connectivity issues. Initially, it connected fine and functioned well. Now, i am having troubles getting it to connect to my computer at all. i have turned off the keyboard, unplugged and plugged the receiver in, then turned the keyboard on; plugged the receiver in while the keyboard is on; changed usb ports; restarted the computer; all without success. Any help or insight would be appreciated.