Apple BT keyboard connection woes

First time poster here... I did search, but may have missed something -- So go easy on me!

Anyway, I have several macs at home and a bunch more at work. I have only experienced this problem twice in the last year so my track record is pretty good. However, I don't use that many Apple BT keyboards (2 actually, and both have had this problem).

The last BT keyboard problem was a year ago, I took it to the Apple store and exchanged it.

Now, the newest of my Apple wireless keyboards suddenly started experiencing connection problems after it had worked flawlessly for a month. It came with a new i7 iMac and has only ever been paired with this Mac. This iMac may be within about 40 feet of 3 other Macs in the house with BT, the rest are beyond BT range. **none** of the other 9 Macs in the house are using a BT keyboard, several are using BT magic mice.

The symptoms: When I power up the iMac it can't find the keyboard. While OSX is on the login screen searching for a keyboard, I have to toggle the power switch a BUNCH of times before the OS pairs with the keyboard. Sometimes I have to type in the pairing key sequence, sometimes it just pairs under the old settings. I do not want to use one of my spare USB keyboards. Before I take this one back, I thought I would find a popular forum and see if someone can shed light on this dilemma.

Details: Yes, it has brand new batteries. No, it hasn't been dropped. The **only** things added to the home in the last month are three 24" LED Apple monitors (about 30 feet away from this keyboard), Bose companion 5 speakers (within 3 feet of the keyboard and connected to the i7 iMac), and a set of Bose companion 2's to a mac that's upstairs and out of range.

Does this one need to go back also? Or, is there some issue with these BT keyboards that I am not aware of?

Thanks for the assist,

DR