I received this from plusnet support as a response to my ticket ID: 20265469 regarding unplayable high ping times in TOCA Race Driver 3. These high ping time started after I came back from holiday end of August (I'd been away for 3 weeks so problem start is unknown):
"Dear Mr Jonathan Gould,
We have asked our wholesale broadband suppliers to turn interleaving on on your phone line to try and fix your current broadband problem.
Interleaving is a form of error correction that helps to improve the stability of high-speed broadband. One drawback of interleaving is that it can increase ping times, which may cause problems for online gamers."
Great! Increase my ping times further why don't you?
[Moderator's note by Tom (tomspcs) : Removed swearing bypass in thread title as it was stopping the thread being accessed.
That looks like an automated reply, a script is set to run on all intermittent connection faults to enable interleaving as most of the faults that are raised via this path (there's a question which asks whether the connection is dropping or a speed problem that determines whether it goes to intermittent faults or speed faults pool).
Looks like one of the faults guys has already requested interleaving be turned off for you.