The EastEnders episode number count thing is odd. According to this page on an EastEnders fan wiki
- yes, I know, but it looks to be correct - the episode numbers have been reset three times.
Firstly when they went to three episodes a week in 1994, but they still celebrated the ‘41st episode’ as being the 1000th episode
Secondly when they went to four episodes a week in 2001, and so they celebrated the ‘1000th episode’ again in 2006
And apparently they were reset for a third time in 2009, when they decided to retroactively renumber all previous episodes to have consecutive counting!