Alignment indicators (inch) disappear after certain number of detail sectoins

A client of ours has quite a large letter, consisting of detail section going up to 'bo' (a -> aa -> b...).

Detail section 'ap' still shows the indicators, any section below, the indicators disappear:

http://i.imgur.com/6chqwL3.png

We are seeing this issue in CR XI.5 and CR 2008 SP1.

Does anyone else have this issue?

Pointers?