I installed Windows8 and the same problem with WIFI association from restart/sleep. The Intel WIFI Event logs captured the following error numerous times before I got associated to WIFI.
18,S24EvMon,01/16/2013 22:46:14,Success,Driver,SYSTEM,RxAssocResp 00:04:ed:26:c8:c4 13 -33
19,S24EvMon,01/16/2013 22:46:14,Success,Driver,SYSTEM,RxAuthSuccess 00:04:ed:26:c8:c4 13
20,S24EvMon,01/16/2013 22:46:14,Information,Driver,SYSTEM,ATC 00:04:ed:26:c8:c4 DH-WIFI 13 RSSI=-33
21,S24EvMon,01/16/2013 22:46:14,Information,Driver,SYSTEM,AddToExclude 00:04:ed:26:c8:c4 DH-WIFI 13 WEV_EXCLUDE_LIST_REASON_802_11_ASSOC_FAILURE
Just before my 1 year support ended I decided to contact DELL and I am glad I did. The DELL support is great. After initial troubleshooting where the problem was reproduced on fully restored machine they sent me a new card.
After inserting new card I instantly got connected (always on first try) on Win7 Home, Windows7 Ultimate, Win8, no above errors anymore neither Windows System Event ID 5002, 5005 errors from NETwNx64 service. I didn't need to change any settings.
I wish I contacted DELL a year ago. Problem SOLVED.
Model: 62230ANHMW
New card:
CN: 0XXG96-36214-2BA-0788-A02
TA: E97664-009
Old card:
CN: 0XXG96-36214-1BT-005A--A02
TA: E97664-006