KEF Warranty work

Does anyone have experience with Kef warranty work?
More info please. Problem, model and age.
model 4~2 four years old, problem was a noticable difference in the bass output between the two speakers that appeared to get worse over time (measured by myself with a Radio Shack SPL meter to be 3 +/- dB.) They were taken into the original dealer August 2005. They first off replaced both bass drivers in one speaker - said was blown due to distortion, but would not elaborate. Then they replaced the bass drivers in the other. Then they replaced the mid bass drivers (assuming in both speakers.) Then they replaced the crossovers (again assuming both). Stated there was still something not quite right and stated there was another crossover in each speaker that they are not able to get to (??). The speakers were then sent to the Canadian distributor, and last I heard they are checking with Kef in the UK to see if parts are still available.
Not sure what the cause was...I do not recall playing at an excessive level (was connected to a Sunfire Signature amp.) Not able to get an answer as to the cause and am also concerned with the length of time in affecting the repairs (the dealer has stated this will be covered under warranty.
Have talked to numerous people who state that they may have been over powered, may have been a fault in the manufacture, may be due to woofer pumping due to TT feedback.
Any ideas would be appreciated, and also any experiences with Kef warranty (in regards to timely service) would be appreciated
Kef is an established and venerable British manufacturer of loudspeakers. On one accasion, I had warranty work on a pair of Reference 4 speakers at the US Headquarters in Marlboro, New Jersey. Kef replaced the speakers with 4.2's.
That sums up my experience with Kef. It is an honorable company to do business with.

Below are 2 locations:

KEF America
10 Timber Lane,
Marlboro, NJ 07746
Telephone: (732) 683 2356
Fax: (732) 683 2358

KEF Audio (UK)
Eccleston Road, Tovil, Maidstone,
Kent, ME15 6QP, U.K.
Telephone: +44 (0) 1622 672261
Fax: +44 (0) 1622 750653
My counterpoint amp blew up,Surprise Surprise, and also took out the woofers in my 105,3.Counterpoint was well on their way to defunck, but did repair the amp.They did not feel that they should cover the speakers they took with them, so Kef in NJ did a great woofer replacement.I took the 2 hour ride to pick them up and kef offered a wonderfull deal on the newer model 4, apparently a dealer demo with a full warrantee,looked and sounded great for $3000.00. So I sold the 105.3 and kept the newer model. Very reasonable folks,Happy, and very satisfied.
Is the amp still working?