does not display all maps for a days activity

pytrainer 1.72 on Ubuntu 11.04.

If I do a days activity such as a ride in the early morning, a short ride at lunchtime, and a further ride late afternoon, sometimes pytrainer will not display all the activity on the map. This seems to be random, in that sometimes it works, others not.

It's more of an annoyance than anything else as the software works fine other than this minor irritation.