Steps to diagnose SNU5600 disconnection problem

I have a Philips SNU5600 WiFi dongle plugged into two machines (ie I have two SNU5600 dongles, one in each machine). One machine is running 10.10 and the other is running Linux Mint.

The dongles work absolutely fine, except if I do a lot of file transfers to a NAS attached to the wireless router. After a while the connection to the router will go.

To get the connection back I either need to run sudo /etc/init.d/networking restart or I need to unplug and plug in again the dongle.

Otherwise the dongle works fine (web browsing, streaming, etc).

Output of lsusb:

Bus 002 Device 003: ID 0471:1236 Philips (or NXP) SNU5600 802.11bg

Output of lsusb -v at http://pastebin.com/dXYKkF01

What steps should I take next to resolve this? Is it a known problem?

Could it be the router? It is a 3Com "OfficeConnect Wireless 11g Cable/DSL Gateway Version 1.02.15".

Edit I am in France and the dongle was configured for the US region. I used the following command to change this:

sudo iw reg set fr

This may have made things better, but I can't be certain.

Edit 2 Disconnect happened at 19:48 and I reconnected at 20:00 - I have some logs:

• /var/log/debug http://pastebin.com/saB4MPpB
• /var/log/messages http://pastebin.com/qEHAL9Sj

This happened in debug when the disconnect happened:

Mar  9 19:36:54 rich-pc kernel: [  211.824126] cfg80211: Found new beacon on frequency: 2467 MHz (Ch 12) on phy0
Mar  9 19:48:26 rich-pc kernel: [  904.483214] No probe response from AP 00:0d:54:9e:71:b8 after 500ms, disconnecting.
Mar  9 19:48:27 rich-pc kernel: [  904.711404] cfg80211: All devices are disconnected, going to restore regulatory settings
Mar  9 19:48:27 rich-pc kernel: [  904.711412] cfg80211: Restoring regulatory settings while preserving user preference for: FR

And this covers messages at the same time plus when I unplugged and plugged in the dongle:

Mar  9 20:00:22 rich-pc kernel: [ 1619.685072] usb 1-3: USB disconnect, address 2
Mar  9 20:00:26 rich-pc kernel: [ 1623.630015] usb 1-3: new high speed USB device using ehci_hcd and address 3
Mar  9 20:00:26 rich-pc kernel: [ 1623.930015] usb 1-3: reset high speed USB device using ehci_hcd and address 3
Mar  9 20:00:26 rich-pc kernel: [ 1624.082780] zd1211rw 1-3:1.0: phy1
Mar  9 20:00:26 rich-pc kernel: [ 1624.133849] zd1211rw 1-3:1.0: firmware version 4725
Mar  9 20:00:26 rich-pc kernel: [ 1624.173847] zd1211rw 1-3:1.0: zd1211b chip 0471:1236 v4810 high 00-1d-19 AL2230_RF pa0 g--NS
Mar  9 20:00:26 rich-pc kernel: [ 1624.176228] cfg80211: Calling CRDA for country: US
Mar  9 20:00:26 rich-pc kernel: [ 1624.179328] cfg80211: Current regulatory domain intersected:
Mar  9 20:00:26 rich-pc kernel: [ 1624.179332]     (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
Mar  9 20:00:26 rich-pc kernel: [ 1624.179335]     (2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A, 2000 mBm)
Mar  9 20:00:26 rich-pc kernel: [ 1624.179338]     (5170000 KHz - 5250000 KHz @ 40000 KHz), (N/A, 1700 mBm)
Mar  9 20:00:26 rich-pc kernel: [ 1624.179340]     (5250000 KHz - 5330000 KHz @ 40000 KHz), (N/A, 2000 mBm)
Mar  9 20:00:26 rich-pc kernel: [ 1624.179343]     (5490000 KHz - 5600000 KHz @ 40000 KHz), (N/A, 2000 mBm)
Mar  9 20:00:26 rich-pc kernel: [ 1624.179345]     (5650000 KHz - 5710000 KHz @ 40000 KHz), (N/A, 2000 mBm)
Mar  9 20:00:26 rich-pc kernel: [ 1624.233713] ADDRCONF(NETDEV_UP): wlan0: link is not ready

It looks like this is a known problem with the driver in question.

Any ideas whether this is likely to be fixed in the next release of Ubuntu?