Sorry, that problem also exists in the linux-backports-modules.

~$ uname -a
Linux buzz-dee-laptop 3.2.0-24-generic #37-Ubuntu SMP Wed Apr 25 08:43:22 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux

~$ dmesg | grep ath
[    9.817315] ath5k 0000:14:00.0: PCI INT A -> GSI 19 (level, low) -> IRQ 19
[    9.817328] ath5k 0000:14:00.0: setting latency timer to 64
[    9.817411] ath5k 0000:14:00.0: registered as 'phy0'
[   10.397277] ath: EEPROM regdomain: 0x65
[   10.397281] ath: EEPROM indicates we should expect a direct regpair map
[   10.397287] ath: Country alpha2 being used: 00
[   10.397289] ath: Regpair used: 0x65
[   10.476684] ath5k phy0: Atheros AR2425 chip found (MAC: 0xe2, PHY: 0x70)
[12227.748534] ath5k 0000:14:00.0: restoring config space at offset 0xf (was 0x100, writing 0x10b)
[12227.748551] ath5k 0000:14:00.0: restoring config space at offset 0x4 (was 0x4, writing 0xf8200004)
[12227.748556] ath5k 0000:14:00.0: restoring config space at offset 0x3 (was 0x0, writing 0x8)
[12227.748563] ath5k 0000:14:00.0: restoring config space at offset 0x1 (was 0x100000, writing 0x100007)
[12837.066051] ath5k phy0: gain calibration timeout (2412MHz)
[12837.396068] ath5k phy0: calibration of channel 1 failed
[12839.970743] ath5k phy0: gain calibration timeout (2412MHz)
[12840.565260] ath5k phy0: gain calibration timeout (2417MHz)
[12841.164132] ath5k phy0: gain calibration timeout (2422MHz)
[12841.657339] ath5k phy0: gain calibration timeout (2427MHz)
[12842.146309] ath5k phy0: gain calibration timeout (2432MHz)
[12842.632622] ath5k phy0: gain calibration timeout (2437MHz)
[12843.234650] ath5k phy0: gain calibration timeout (2442MHz)
[12843.718672] ath5k phy0: gain calibration timeout (2447MHz)
[12844.314516] ath5k phy0: gain calibration timeout (2452MHz)
[12844.799420] ath5k phy0: gain calibration timeout (2457MHz)
[12845.283034] ath5k phy0: gain calibration timeout (2462MHz)
[12845.768027] ath5k phy0: gain calibration timeout (2467MHz)
[12846.225611] ath5k phy0: gain calibration timeout (2472MHz)
[12846.682932] ath5k phy0: gain calibration timeout (2412MHz)
[12851.686041] ath5k phy0: gain calibration timeout (2412MHz)
[12852.281321] ath5k phy0: gain calibration timeout (2417MHz)
[12852.877394] ath5k phy0: gain calibration timeout (2422MHz)
[12853.363283] ath5k phy0: gain calibration timeout (2427MHz)
[12853.957287] ath5k phy0: gain calibration timeout (2432MHz)
[12854.553355] ath5k phy0: gain calibration timeout (2437MHz)
[12855.039054] ath5k phy0: gain calibration timeout (2442MHz)
[12855.633532] ath5k phy0: gain calibration timeout (2447MHz)
[12856.237942] ath5k phy0: gain calibration timeout (2452MHz)
[12856.867259] ath5k phy0: gain calibration timeout (2457MHz)
[12857.501962] ath5k phy0: gain calibration timeout (2462MHz)
[12858.098592] ath5k phy0: gain calibration timeout (2467MHz)
[12858.550674] ath5k phy0: gain calibration timeout (2472MHz)
[12859.003382] ath5k phy0: gain calibration timeout (2412MHz)
[12859.470747] ath5k phy0: gain calibration timeout (2412MHz)
[12859.960119] ath5k phy0: gain calibration timeout (2417MHz)
[12860.454983] ath5k phy0: gain calibration timeout (2422MHz)
[12860.945527] ath5k phy0: gain calibration timeout (2427MHz)
[12861.548105] ath5k phy0: gain calibration timeout (2432MHz)
[12862.149148] ath5k phy0: gain calibration timeout (2437MHz)
[12863.237947] ath5k phy0: gain calibration timeout (2447MHz)
[12863.840578] ath5k phy0: gain calibration timeout (2452MHz)
[12864.455031] ath5k phy0: gain calibration timeout (2457MHz)
[12865.061292] ath5k phy0: gain calibration timeout (2462MHz)
[12865.665834] ath5k phy0: gain calibration timeout (2467MHz)
[12866.122011] ath5k phy0: gain calibration timeout (2472MHz)
[12866.575852] ath5k phy0: gain calibration timeout (2412MHz)
[12871.582184] ath5k phy0: gain calibration timeout (2412MHz)
[12872.070125] ath5k phy0: gain calibration timeout (2417MHz)
[12872.556329] ath5k phy0: gain calibration timeout (2422MHz)
[12873.155251] ath5k phy0: gain calibration timeout (2427MHz)
[12873.640461] ath5k phy0: gain calibration timeout (2432MHz)
[12874.239180] ath5k phy0: gain calibration timeout (2437MHz)
[12874.725013] ath5k phy0: gain calibration timeout (2442MHz)
[12875.323658] ath5k phy0: gain calibration timeout (2447MHz)

~$ sudo modprobe -rfv ath5k
rmmod /lib/modules/3.2.0-24-generic/updates/cw-3.3/ath5k.ko
rmmod /lib/modules/3.2.0-24-generic/updates/cw-3.3/ath.ko
rmmod /lib/modules/3.2.0-24-generic/updates/cw-3.3/mac80211.ko
rmmod /lib/modules/3.2.0-24-generic/updates/cw-3.3/cfg80211.ko

after suspend:
--------------------

~$ sudo modprobe -v ath5k
insmod /lib/modules/3.2.0-24-generic/updates/cw-3.3/cfg80211.ko 
insmod /lib/modules/3.2.0-24-generic/updates/cw-3.3/mac80211.ko 
insmod /lib/modules/3.2.0-24-generic/updates/cw-3.3/ath.ko 
insmod /lib/modules/3.2.0-24-generic/updates/cw-3.3/ath5k.ko