This is a known issue affecting SpeedTouch routers with v.6 firmwares...
When I emailed SpeedTouch UK Support, they denied there was an issue. However there are several postings here and SpeedTouch NZ fourm. Apparently a new firmware should be made available shortly...
Not just v6 firmware. The problem has been present at least since the first publicly available beta versions of IE7 and affects the latest v5.4.4.1 firmware for the ST585 v5.
Several months ago ST Tech Support said that a v6 version of the firmware would be published for the ST585 v5, but nothing has materialised. I just fear that means there will be no further firmware releases at all for the v5...
I'm using a Belkin7633 and had a very similar problem, it was cured when Zonealarm suddenly decided to allow it as an update. This was after about an hour of trying to sort it. Might be worth looking in this direction also.
Sent Speedtouch Support an email last night about it and their response is they are aware of the problem and they are working with MS to resolve it. The workaround is to use another browser or earlier version of IE.
Tim
ZeN & freenetname ST510v4 (4.3.2.6 CU Firmware) on 8 Meg Active
Check my bad boy speeds out onZeN