Thank you Sleepyhead!
I will try to put the door seal back to the washer again later today. It is really a lesson that tells me one thing- if one wants to do DIY on his washer,then he should consider buying one that is front panel removable.
I have been using my Zanussi FLS823C since 1997. Last week I found a small hole in the door seal (at 8 o'clock position). This caused a leak but wasn't serious. I then took out the seal and tried to install it again so that the hole is in the 12 o'clock position in order to avoid leak...