If you live in a hard-water area, it might also be worth checking the water inlet, which caused a similar symptom on my machine. I found that the hot water in-flow had got blocked with limescale at the point where it enters the soap-dispenser tray (at the top left of the machine, looking from the front).
It only takes a few minutes to check this:
1) Disconnect from electricity supply.
2) Remove lid (two screws each side near the front).
3) Find hot water inlet valve, remove the black hose below it, and blow into this hose while the other end of the hose is still connected to the soap-dispenser tray. If air flow is difficult then remove the other end of the hose from the soap-dispenser tray and poke a screwdriver or drill bit in to the hot-water path through the soap-dispenser to clear any limescale from it.
In this case, the flashing lights will be indicating a failure to fill the machine with water as quickly as the software expects, so this problem will happen at a different point in the wash-cycle from those covered in the excellent previous reply to this question.
While you have the machine dismantled, it may be worth clearing all potential blockage troublespots on both water-exit and water entry. This could save you having to roll your sleeves up again and fix another problem soon afterwards.
Hope this helps,
Richard W
Richard W, December 2007