Fibre now erratic

[#1]

I've been running on the Fibre extra package since the beginning of June. Since day one, I've not had any problems, and the service has been fast (generally >25Mb/s) and reliable, until the last couple of days. Performance is now erratic, pages are slow to load, or even fail to load at all. Everything is fine at this end. I've rebooted the router and BT VHDSL box. While the VHDSL box appears to connect ok, the router was, for a time, stuck staying 'connecting'. It would make a connection, then drop again. It's been stable for the last 36 hours though. I'd had similar issues when I used to be on standard ADSL, and this was an exchange or PN issue.
So, I don't think it's a local problem, but would this be a standard PN support call?

[#2]

Hi tman247,
Our connection logs show that there were some disconnections on 21/08/11:

However since that point your line has re-stabilised.  Your modem is connected at 39.99Mbps so there certainly shouldn't be any issues with the speed of the connection.  The disconnections seen are likely to be a maintenance task or a local disruption to service of some kind.
Have your speeds returned to normal now or are you still experiencing erratic performance?  If the latter you should run the BT speed tester at http://www.speedtester.bt.com/ and post the results.