Constant wifi drop & disconnect

Question

My one month old iMac does not maintain an interent connection for very long. Sometimes it stays connected for <maybe> an hour, but  MORE often it drops either the wifi signal all together or just stops connecting to the internet... when it does seem to have a connection it is VERY slow.
My solution: turn off Wifi wait a few seconds and turn it back on... which is very annoying, but that fixes it.
I have the latest software across the board. I'm running wifi on Time machine. My signal is strong. I have a Powerbook and iPad that connects to it without issues (for a couple of years its been fine until this iMac problem).
Any suggestions?

Answer 1

There are actually many threads on this subject around here, like this one:
https://discussions.apple.com/thread/3190651?start=0&tstart=0
There are also many articles on Lion wifi drops. Here are my two cents:
I have a 4 month old iMac running Lion and for the first three months it worked beautifully, but I started having problems with my internet provider and they sent over a technician who changed my modem/router to a new one and configured a new network. He never even touched my iMac, it was all done on one of the PCs in my house, and immediately after that my iMac started dropping the connection all the time. All the other computers in the house (pc and Snow Leopard mac) are working fine.
I have read a thousand threads on this subject and apparently it is a known issue with Lion. There are many suggestions for solutions and I've tried every single one of them, including removing the network in the system preferences panel and then adding it back; or adding DNS servers to the DNS list; or changing the channel on your network (it should be lower than 11). If you search for threads here you'll find many of these supposed solutions, so I'm going to cut to the chase. The only one that worked for me is this:
Open Terminal (type Terminal into Spotlight)
Paste the following line exactly as is into the Terminal window:
  ping `route get default | awk '(/gateway/){print $2}'`
Press enter
DON'T close the Terminal window. Just press cmd+H to hide it and leave it running in the background.
It is NOT a permanent solution and you have to do it every time you restart your computer, and you have to keep Terminal running on the background. It is a huge pain, but I find that connection drops every 10 minutes is an even bigger pain. Basically what this command does is send signals to the modem every couple of seconds so that the connection doesn't drop from being inactive. It won't affect anything else on your computer and it's not very system-consuming.
This seems to be the only way to have a steady connection for now, until Apple addresses the situation. They just issued an update regarding this issue last week or so, so I suggest you try to keep your system as updated as possible. This update only worked for me till my next startup, though.
However, like I said the problem only started after the technician changed my modem/router and network, so I suspect this is not a Lion problem, but a network problem. The only different thing I can think of that was done with the new network is that I used to have a WEP password and now I have a WPA2 Personal password. I intend to delete this new network and create a new one from scratch, but I haven't had the time yet. I suspect though that there could be some incompatibility with the actual machine (the modem/router), and not the network. I have not found any info on this and have not yet been able to figure out.
I hope this helps, if I find out something more I'll post about it, but in the meantime check out the other threads and google some articles, there are many different answers and opinions on this.