We recently found a bug that may silently cause problems with many simulations. The bug causes problems in the following situation:

In this case, the SpikeContainer object would be improperly initialised and many spikes may be lost. The latest development version fixes this. See ticket #33 on our trac. If you have code running on an older version and think your code might be affected, please get in contact on the briansupport@googlegroups.com list.