Sorry folks, I can't really make a bulletproof case, and it sounds crazy,
but I have the feeling, if I don't use the mouse every hour or so, Tixati falls asleep.

Its really like Tixati going down from 500 KB/s to 20 KB/s and then 0, if I let it run unattended.

The problem is probably another program or the OS, but I can't pin it down.

Am I alone?

tixiti doesnt have a sleep feature afaik. you can check your computer sleep settings by going to:
start->control panel->power options->change plan settings.