WiFi doesn't restore like it used to after sleep

There is an issue if Time Machine was running when the system went to sleep, that after wakeup Time Machine holds a "dead" network connection and prevents the reconnect. Time Machine will eventually give up, and at that point the system will reconnect. You can make this happen faster by stopping the backup, but even this will take a while. You may also need to turn off WiFi and turn it back on again. In my experience this works more than 90% of the time. If you are unlucky enough to hit the 10% the best solution is to reboot.

Yes, I've noticed if you kill WiFi it stops TM and then you can reconnect. But I don't remember this being an issue with Snow Leopard. Hmmm.

Yes, it seems almost definite it is an issue with Time Machine - what GlennW described is exactly what is happening to me.

Isn't it ridiculous that Apple can't sort out glitches between its own devices?! I mean, it isn't as if the Time Machine is cheap - it's not really something I'm willing to turn off or constantly interrupt in order to remedy my wifi. Come on Apple!

This does appear to be a Lion problem, yes.

Not trying to make excuses for Apple, but the intersection of automated backup, wireless networking and sleep/wakeup is a really complex area. There are just so many things going on simultaneously, and getting them all to coordinate seamlessly and transparently is a huge challenge. Despite the occasional glitch - and unfortunately the early versions of Lion seem to have more than their share - in my experience Apple does this better than anyone else.

I enconter the same problem.

sorry, but after being on the phone for 20min and being told that it may be inerference from a cell phone or some other wireless device, the guy hung up on me *$%#$>% no solution from Apple there...

I too am experiencing the same problem.

The last version of Snow Leopard had it too. Now in Lion also.

Everytime I wake my iMac from sleep, the WIFI connection drops out and I have to spend a couple of minutes trying to reconnect to my wireless router. My girlfriend doesnt seem to be experiencing any problems at all with her Macbook Pro.

HOT TIP: I have figured out that my REFRESHING my browser screen, after I get a connection error, the connection is established again and everything starts working again.

i have the same problem with my imac its very very annoying but i have lion on my macbook pro i dont have this issue i spoke to apple about the issue they said they are aware about the problem and the new update will fix the issue the new update has come out and still have the same issue.

never hated my mac since this started to happen!!!

hopefully they can correct this issue ASAP

I have this issue as well. It's definitely a TM - WiFi interaction issue. I connect to my TM disk over WiFi.

Two Solutions:

1. Don't put your mac to sleep during a backup. Either wait for it to finish or stop it from the menu bar.
2. When you wake the Mac, stop the backup from the menu bar. Once it stops, WiFi will reconnect.

I got off the phone with U.S. Apple Support last week . The Rep said that indeed Apple is aware of the loss of Internet connection and the loss of Wi-Fi connection after awaking from sleep, and the automatic immediate wake from sleep with users of Lion. He said the problem as the Apple Engineers see it is that instead of Lion putting JUST the monitor and harddrive to sleep as it should, Lion is instead put almost all Sytem Functions to sleep as if you had temporarily turned off the computer. Thus the delay in re-establishing your connections.

The rep concluded: A fix is almost finished and will soon be available as a "Software Update."

Hang in there guys ;-)

The Lion wake-from-sleep wireless dropping issue is definitely not Time Machine related. I have the issue on my MBPro - but I don't have Time Machine.

Same problem, on a MBA and dont have time machine.... is so sad that they cant fix this problem,,, it takes me like 20 minutes everytime i want to fins my wifi network again.....

I hate to be the cork in the bottle at a party that is so bubbly... but I have zero wifi problems. And I am not able to replicate anyone elses problem... if you have a problem, bring it to an apple store, or be specific about your problem. Call your internet company, and ask them to increase your speed to at least 6 Mbps. There are a lot of possibilities, a person just saying: oh... it takes me 20 minutes everytime I want my wifi... try to solve the problem. Do something about it. Find out what is wrong by giving specific details about the internet connection speed, the type of computer model you have, the type of router, is it on the business intranet or home wifi, etc etc. I think instead of passing the buck, and saying "is so sad they cant fix this problem," get up and make some phone calls and get it done! Find out a solution, and share what you did, instead of making asumptions that are based on inductive reasoning.

http://compnetworking.about.com/od/dslvscablemodem/a/speedcompare.htm

or

http://www.comcast.com/Corporate/Learn/highspeedinternet/highspeedinternet.html