Custom Settings don't save automatically

On my 50d, I've noticed that if I 'edit' my custom settings (and not re-save), and the camera goes into power save mode, when the camera comes on again (time to take another pic), the settings revert back to their saved registered settings. How do I change it so this will automatically keep them, much like the other modes such as Av/Tv etc do.

Thanks in advance.

Unfortunately, when the camera goes into power save, it acts the same as if you turn the power button off, the custom settings are reset to the stored settings.
This behaviour is consistent in all cameras I have tested 40D, 50D and 7D.
It would have been very convenient it there was a difference between power save and power off, so that temporary setting changes would be kept when coming back from a power save shutdown, but as far as I have been able to find out, there is no setting to make this happen.

The only thing you can do is to extend the "go to sleep" time from the normal (?) one minute to something longer. I usually set it to four minutes, as I seem to not be able to keep my fingers away from the camera for four full minutes.