LinuxQuestions.org - Cant reconnect to wifi network after asus eeepc sleeps

Hello,

Hope I'm posting this in the correct forum. Thought about posting under RedHat, but I'm guessing this is more of a general Linux question. Searched but didn't see any posts which matched my crtieria.

QUESTION:
Whenever I leave my netbook alone for a while and it goes to sleep, when I bring it back up my wifi is no longer connected. And no matter what I've tried, I cannot get re-connected unless I reboot. Then it connects fine again.

Hardware:
Asus 1005HAB eeePC purchased from BestBuy. Came w/ Win7. I installed CentOS 5.5 using free space. Working great so far after 2 months.

Notes:
I was able to get this laptop (netbook) to connect to my wifi router at home. Whenever I boot into X-Windows, I get a prompt to enter my gnome keyring password, then it automatically connects to my wifi router.

After I wake it from sleeping, it shows the network connection has been lost. I can see my network name from the list of wireless networks in Gnome. If I try clicking it, it tries for like 30 seconds then fails.

My wifi router is setup using wpa2. I'm using the NetworkManager service to manage things. wpa_supplicant service is disabled.
I did however, input all my details in my wpa_supplicant.conf file (even though I saw this posted somewhere: "Network Manager ignores any wpa_supplicant.conf settings you use, and use the wpa_cli program to configure wpa_supplicant "on the fly" when it starts")

lspci shows:
02:00.0 Network controller: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) (rev 01)

iwconfig shows:
wlan0 IEEE 802.11bgn ESSID:(snipped)
Mode:Managed Frequency:2.437 GHz Access Point: (snipped)
Bit Rate=1 Mb/s Tx-Power=20 dBm
RTS thr:off Fragment thr:off
Power Management:off
Link Quality=28/70 Signal level=-82 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

Any suggestions appreciated. Thanks!