Atheros Wifi Randomly Slows to Crawl

[thekod]

I'm running a Soekris 5501-70 with a Ubiquiti SR2 and a 12" rod antenna.

Every few days, the wireless absolutely goes to crap…everything slows to a crawl, and if I ifconfig ath0 down or reboot the router, or even change settings sometimes, it goes back to normal.  Is this a known issue, or am I doing something wrong?  I saw a post some time ago about having a lot of errors and slowness, and I've got a lot of in errors, but that occurs whether or not the wireless is slow.

Here's the config for ath0:

		 <opt3><descr>Wifi</descr>
			<if>ath0</if>
			 <wireless><standard>11g</standard>
				<mode>hostap</mode>
				<protmode>off</protmode>
				<ssid>FreeInternet</ssid>
				<channel>1</channel>
				 <authmode><txpower>99</txpower>
				 <distance><wpa><macaddr_acl><auth_algs>1</auth_algs>
					<wpa_mode>1</wpa_mode>
					<wpa_key_mgmt>WPA-PSK</wpa_key_mgmt>
					<wpa_pairwise>CCMP TKIP</wpa_pairwise>
					<wpa_group_rekey>60</wpa_group_rekey>
					<wpa_gmk_rekey>3600</wpa_gmk_rekey>
					 <passphrase><ext_wpa_sw></ext_wpa_sw></passphrase></macaddr_acl></wpa> 
				 <wep><pureg><enable></enable></pureg></wep></distance></authmode></wireless> 
			 <bridge><ipaddr>192.168.2.1</ipaddr>
			<subnet>24</subnet>
			 <gateway><spoofmac><mtu><enable></enable></mtu></spoofmac></gateway></bridge></opt3>