Something like you happened to me. I explain : I was playing with a friend, we both climb up the ladder in the same time. Once we get at the top of the ladder I fell (maybe because there are no more place on the platform since my friend was standing near the ladder).

Here is the video where I fall from the ladder (check at 21") :

http://www.youtube.com/watch?feature=player_detailpage&v=B3FZ7d8G99s#t=1250

NB : The video is in french but you'll understand just with watching.

This is a duplicate report and/or the developers are already aware of this bug/problem.

Please check the feedback tracker to see if an issue exists before creating a new one and instead vote the original one up so the developers can see it's a common problem. (Most of the most popular will be up top if ordered by Priority).

You can also use the 'Filter' textbox to search through existing reports using a keyword if it's not close to the top.

A list of important bug/issues that the developers are already aware of can also be found on the DayZ Forums:

http://forums.dayzgame.com/index.php?/topic/153994-early-access-important-information-known-issues/ [^]

Any additional images of the problem in question is always appreciated (if possible) and can be added by using the 'Upload File' section within a bug report.

I've added the original as a relationship which you can use to post any additional information in the one place.

Cheers