Dropped from 3.5 to 3

[#1]

My speed has dropped over the last 2 weeks

System Up Time 13:21:21
Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN PPPoA 93471 182314 0 197 8114 08:40:00
LAN 100M/Full 0 0 0 0 0 13:21:00
WLAN 11M/54M 273800 163890 0 8714 435 10:37:35
ADSL Link Downstream Upstream
Connection Speed 3360 kbps 448 kbps
Line Attenuation           41.0 db 24.0 db
Noise Margin           13.0 db 23 db
It looks like the noise margin has increased a fair bit - it used to be below 10. When I first resync its about 4200 kbps but it looks like after midnight the connection drops.
Ive done a few manual restarts of the router recently as Ive tried out different security settings to get my daughters blackberry to stay connected wirelessley but id say only about 5-6 over the last 3-4 days.
Anything I can do it get back up?
Netgear  DG834Gv5
Firmware Version V1.6.01.34

[#2]

It looks like your noise margin has increased to 12, presumably due to the recent trial and error testing you've carried out.
Someone with a lot more know-how than me would probably say that with your line attenuation you should be getting a fair bit more line speed. They would then ask if you are connected to the master or first socket and whether your ring-wire has been removed.
It does look like there are some changes afoot with the DRM system but whether that would allow a bit of experimentation without any penalisation I don't know.
My off the wall idea would be a DRM happy hour. DRM switched off for an hour say 6-7pm Saturday so everyone can switch on and off and fiddle with their routers to their hearts content.