More info???
Your question needs more information in order to get an answer...
which GPSR?
what software?
what camera overlay?
etc etc
The only one i'm familiar with is the Garmin adapted one available from this forum, and that isn't "updated" direct to the unit, the user has to download the new updated map overlay, then re-update it (with all the other maps they require) to their Garmin GPSR, this process deletes all previously stored maps on the GPSR and uploads the new ones you've just selected, inlcuding the now updated Speed camera overlay map.
Does that help? Answer your question?