THP engine problems, lack of power 2000-3000rpm

I've got a 207cc and have been pleased with it for a couple of months. The
THP 150 engine was initially quite powerful given it's only a 1.6 and the
boost threshold was about 1500rpm. From there on up the power was pretty
much linear.

Now though after a new months I've noticed a flat spot between 2000 and
3000 rpm - this happens on occasions, usually when you've just pulled out
onto a roundabout!

I did a little googling and there are some mentions of this on both the 150
and the 175 bhp THP engines, and also being experienced with the same
engine in the BMW mini, so my problem isn't unique. There is some
suggestion the engine mapping is storing invalid values and the problem
goes away if the garage reset the stored values.

One guy has had his car in 7 times with various bits changed with no
change, I wondered if anyone here has any more info? I don't particularly
want unecessary time spent in the garage randomly changing bits. The
salesman knew nothing of these problems when I asked last week.

Cheers,
Dave

Disconnecting the battery for a few minutes will often reset all the stored
values in the ECU.
However, be careful as on many later Peugeots you can muck up the
immobiliser and other bits in the computery if you disconnect and reconnect.
Firstly lower window, then remove key, and close door. LEAVE for 5 minutes.
Then disconnect battery. Again leave for 5 minutes or more for valued to
reset to standard.
Reconnect battery and again leave for a couple of minutes, then lean through
open window and turn on the lights. This is to wake up the computer.
Then you should be able to start as normal.
If you don't follow this you might not be able to start the engine again
without a costly visit to a main dealer.