Why does 192.168.1.254 no longer access my router?

[#1]

Spoke to a CSC the other day who contacted me to say he'd reset the line and would arrange for a visit from BTOR because of my low speeds (<0.5 Mbps d/l, 0.3 u/l). Good news, I thought.  The engineer turned up and replaced the BT master socket yesterday (1½ hours after his last scheduled time), but the speed has actually dropped slightly since. The line reset performed before his appointment appeared to have had a greater effect on d/l speeds (1.37 Mbps d/l, no change u/l), though I'm unable to access the router stats to check if there are any line faults still being recorded. So although my speed has improved since the fault was reported it's still under half of my estimated speed when I signed up and half of what my speed was (with the line fault!) before I migrated to PlusNet. And to cap it all 192.168.1.254 no longer accesses my router. Is it possible the access been changed remotely? I am seemingly unable to check my router stats without performing a reset, which I don't want to do as I've previously being informed that rebooting/turning off the router was having an effect on my line speeds, and which, frankly, I felt was being used as a get out of jail card by PlusNet to avoid me escaping from my BB contract.
I have asked several times what effect turning off/rebooting the router should have, particularly after the so-called "training period". I'm still not convinced there isn't some sort of capping going on, whether it's in the form of DLM or whatever minimum service PlusNet can legally get away with providing without too much fuss from the consumer.

[#2]

Assuming you're on windows, click on start, run and type CMD
At the box, type ipconfig
Post back what your default gateway is.
Type exit to close the DOS box by the way.

[#3]

Same as above, 192.168.1.254.

[#4]

Very strange.
Have you tried a different browser ? It is probably something glaringly obvious but I don't use the PN supplied router so I can't help much more I'm afraid

[#5]

Just to rule out finger problems try this http://192.168.1.254/cgi/b/dsl/dt/?ce=1&be=0&l0=1&l1=0
If that doesn't work can you check the hosts file to see if a redirect has crept in

[#6]

Yep, tried Firefox too. Think a new router might be called for, as I'd like to rule out any possibility of any disconnects being caused by the router as one or two threads suggest. I don't want to have too many resets or them to last any longer than necessary so I might set it up on a spare computer. Now there's a thought, will see if I can connect with that before shelling out on a new router.
Ha ha, yes, Oldjim, used cut and paste to rule PICNIC out :). The shortcut hangs too. Hosts file clean, nothing except original #comments.
Will check back later as I have other things to do.

[#7]

when you check back - try disabling your internet security package

[#8]

If all else fails, you may need to do a factory reset of the router (a single disconnection shouldn't do any harm).

[#9]

I had the same problem 5 days ago.
I switched off the power to the router and left it for 10 minutes. Then switched on again and all worked perfectly. 

[#10]

Quote from: MrT

I switched off the power to the router and left it for 10 minutes. Then switched on again and all worked perfectly.

Turns out the "have you tried turning it off and turning it on again" did the trick. Thanks MrT, and everyone else for the suggestions.
Not sure if rebooting has slowed the line down at all as a CSC claimed to have got 2.2Mbps testing my phone line earlier, but a BT Wholesale test is coming in at 1.87Mbps. Not sure what to believe any more as the BT line profile's only coming up as 2.09 Mbps