[info4u]

I would say your problem lays in 2 parts

1) The stb memory may be affected causing the delay between channel changes, Im pretty sure you have already been advised this but restart the STB by giving 20 seconds between switching back on from the mains.

2) Low signal strength
This is the reason why your getting freezing pictures, this has nothing to do with the box its self if its causing intermittent sound and imaging.
Adjusting the scart socket will not do anything since your getting pixelated images.

Solutions available
Call 151 for an engeneer (earliest is always 2 days from the day of the call), but this will vary on the demand for technicians in your area.
This is for Sales, Collections, special requests (Such as moving a box to another room) and fault repairs.
So if your told there is no technicians until X date for example 5 days later from the call, this means there could also be request for installs and moving boxes and not solely down to faults.

However if your not happy with the dates available, you can ask for the representative to call operations (Who deal with direct contact with technicians and availability).
99% of the time what is already shown on the computer screens is what is available however on some circumstances they are able to obtain a technician from a neighbouring area or squeeze in 1 additional visit.

The technician will then check the signal levels coming into the property and may adjust the reading on the STB its self.

RESTART THE STB BY UNPLUGING FROM THE MAINS
HOLD DOWN THE UP AND DOWN BUTTONS TOGETHER
POWER BACK UP
AND HOLD THE BUTTONS UNTIL A BLUE MAINTENENCE SCREEN APPEARS
About page 7-9 you will see the signal strength screen
Using your remote you can change the signal being read

ALL SHOULD SHOW OK and in GREEN
AMBER = SOSO
RED = POOR SIGNAL

As this is constant keep an eye on it for at least 2 minutes before adjusting and saving your settings

Goto the COLD RESET screen and press TV, your box will reset and all should load back up
IF NO JOY then it is more technical then just changing the signal being read.

HOWEVER! IMPORTANT!!!

I dont recomend you do this unless your 100% sure, since if you muck this up and a technician comes out and finds you have tampered with the signal, they will then see this as your own doing and will charge you £25 or what ever the cost now is under Virgin Media's prices (£25.00 when Telewest)

There are some teething problems with the software they use on the boxes which is slowly being ironed out

Hope this helps you out

You do not need to take out the card and whipe it since that will not have an affect on channel changes or crackling images, if it was the CARD it would show a message box saying your card may be faulty or your not subscribed to this channel