I've responded to a couple of threads here about the TalkTalk branded DLink DSL-2780 router/modem, specifically that on the current firmware, some of the line stats are reported the wrong way round.
This is fixed in an update of the firmware, which is linked to in the first post of this thread on the TalkTalk members forum http://talktalkmembers.org/forums/showthread.php?t=83991
I've been running this firmware for a while, and not had any problems with it.
There's also TalkTalk updates for the DSL-2680, Huawei HG520b and Huawei HG532 as well as the DSL-2780.
(and, should you want, there's copies of the original "current" firmwares there too.)