So please try the following patch (instead of the original one)
which should fix all the unailgned accesses in do_rx.

Cheers,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} [off-list ref]
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diff --git a/drivers/net/wireless/zd1211rw/zd_mac.c b/drivers/net/wireless/zd1211rw/zd_mac.c
index a903645..d06b05b 100644
--- a/drivers/net/wireless/zd1211rw/zd_mac.c
+++ b/drivers/net/wireless/zd1211rw/zd_mac.c

@@ -1166,15 +1166,16 @@ static void do_rx(unsigned long mac_ptr)
 int zd_mac_rx_irq(struct zd_mac *mac, const u8 *buffer, unsigned int length)
 {
 	struct sk_buff *skb;
+	unsigned int hlen = ALIGN(sizeof(struct zd_rt_hdr), 16);
 
-	skb = dev_alloc_skb(sizeof(struct zd_rt_hdr) + length);
+	skb = dev_alloc_skb(hlen + length);
 	if (!skb) {
 		struct ieee80211_device *ieee = zd_mac_to_ieee80211(mac);
 		dev_warn(zd_mac_dev(mac), "Could not allocate skb.\n");
 		ieee->stats.rx_dropped++;
 		return -ENOMEM;
 	}
-	skb_reserve(skb, sizeof(struct zd_rt_hdr));
+	skb_reserve(skb, hlen - ZD_PLCP_HEADER_SIZE);
 	memcpy(__skb_put(skb, length), buffer, length);
 	skb_queue_tail(&mac->rx_queue, skb);
 	tasklet_schedule(&mac->rx_tasklet);