Keyboard won't re-pair with Mac Pro

OK, here it goes...

I have a 2007 Mac Pro (2 x 3 GHz Dual-Core Intel Xeon, 4 GB 667 MHz DDR2 FB-DIMM, 500GB HD) running OS X 10.6.8, with zero hardware issues this entire time.

With it, I have the A1016 wireless keyboard. Never had issues with it either. Yes, some slight, temporary loss of signal here and there over the past 7 years, but nothing that lasted more than a few seconds, and extremely rare.

Yesterday the keyboard loses connection. Seemingly, no big deal.

- OK, I wave it closer to the tower...nothing.

- I turn it off then back on...nothing.

- Batteries were at 47%, but I put some fresh ones in anyway...nothing.

- I restart the computer...nothing.

- I shut off the computer, let it rest a while, turn it back on...nothing.

- I check the Bluetooth preferences. Keyboard is paired, but not connected. No clue why it won't connect.

- I check the keyboard. The green light turns on for a sec then starts blinking as if it is discoverable. After many attempts, it still won't connect.

- I clean the battery port and the keys of the keyboard, just in case. No improvement.

- I remove the device from the Bluetooth pairing and attempt to re-pair.

- All I get is a gray spinning pinwheel that won't find the keyboard.

- I go to Bluetooth Setup Assistant.

- 1 device found: Apple Wireless Keyboard...GREAT!... I click Continue

- "Attempting to pair with Apple Wireless Keyboard"

- Passkey comes up 0000... gray spinning pinwheel...and times out without giving me a space to type it. says "The pairing attempt was unsuccessful"

- I click Passcode Options and select "Automatically generate a passcode...OK...Continue

- The 8 digit passcode appears...gray spinning pinwheel...and times out without giving me a space to type it. says "The pairing attempt was unsuccessful"

- I repeat every option about 50 times. Still nothing.

I have researched EVERY internet forum and have not found anyone with this same issue, nor anywhere near a solution. Apple care is long gone and I'm not paying them $20 to answer my question while sitting on a custom $7,000 Mac Pro and another $2,000 in iProducts. I'm at a loss at this point. If I knew what the issue was, I'd be able to determine if my computer is at fault or my keyboard is at fault. I know my gear is relatively old, but I'm not going to buy new tech if I don't have to. Plus, I'm pretty broke at the moment, so buying new tech would be painful.

I'm a freelance designer and editor with deadlines and limited options until my next paycheck. I'm wirelesly using my iPad as a keyboard for my Mac Pro at the moment, but it's FAR from ideal and is slowing me down.

I would GREATLY appreciate any informatiom and kind advice from anyone who happens to know how to fix this issue.

Thank you in advance!!!