There is a discussion of this going back many months in the previous forum. My initial post there has had over 600 views and I see that an IT administrator with 10 BB has the exact same problem. I have replaced my BB 4 times and all of them behaved the same way with this CISCO WAP4410N:
THE PROBLEM: The 4410 drops the WiFi connection to a Bold 9700 BB (using WAP2). I got an old Motorola about 6 years old out and found it works fine with the BB as does most of the public hot spots. This is an issue with the 4410. An IT Admin has found (an posted in the eariler forum) that for some reason the key change is not accomplished when issued by the 4410 but it works for others. The Admin discovered that if he set the timout on the key change to maximum he only has to restart the 4410s every 10 days.
So I have the 4410 for my 5 computers with which it works fine and beside it the old Motorola for the BB. There is a lengthy discussion of this in the old forum
When I called support about this I was told that "we don't support connections to Blackberry." I hate to have to sell this thing on Ebay and buy another brand becuase of this. Seems that Cisco would fix it.
I think Borders here locally uses the same 4410 as I have the same problem over there. Anyplace else however it is fine.