Mac Powerbook will not reconnect on waking

[#1]

I have a strange problem with my Mac Powerbook connecting to my Thomson TG585
When the laptop wakes after going to sleep, the wireless often does not re-connect to the wifi network.
Sometimes turning the Airport on and off, solves the problem. But often it does not.
If it does not, I get a list of wireless networks to connect to, including the relevant Plusnet one. I choose than and see a prompt for a password. But when I enter the correct password (checked many times) I get an error to say that the password is invalid.
The only solution is to restart the computer, at which point it connects.
As you can tell from the variety of keywords stuffed into this question, I've already been searching for an answer with no luck.
Help, please...
Tim

[#2]

Hi Tim,
We had an issue with Macs/wifi connectivity and the original version of the router's firmware. I can upgrade this remotely for you but your router will be offline for about 10 minutes. Let me know when it's convenient to do this for you.
Jojo

[#3]

I have this issue with a Macbook (10.6.7) and a Cisco 877W CPE

[#4]

Quote from: Joanne

Hi Tim, We had an issue with Macs/wifi connectivity and the original version of the router's firmware. I can upgrade this remotely for you but your router will be offline for about 10 minutes. Let me know when it's convenient to do this for you. Jojo

That sounds great, thank you. The sooner the better please, from my point of view.
Tim

[#5]

Hi Tim,
your router has been successfully updated.
jojo

[#6]

Thanks, Joanne. That's a great relief. It was getting to be a real pain.
Tim

[#7]

I take it it's all working fine now?