I've been using the Nokia "Compteurs" (french) app on my good ol' Lumia 800 which is running 7.5. This application goal is to increment app counters every time you're making a call, sending SMS or using your data connection. In addition to that you can set customized limit for these 3 counters to monitor your monthly consumption.
Two of my friends have been using this app for months without any issue with the exact same device (we bought it at the same time). But for me it's another story: every now and then the app will simply "restart". What I mean is that when launched, the app will show me the first "tutorial" message and all my limits and counters will be gone, exactly as if I never used it. Sometimes it happens after two days, sometimes after two weeks, ...
This app is supposed to run in background, so it will automatically be "disconnected" if the device is on battery saving mode, but I've made sure this wasn't happening since last time.
Do you have any idea what could cause this? Maybe something like Wi-fi/Data/Bluetooth being turned on/off?
Edit: Here is the app link. And now that I read all that page comments, I'm obviously not the only one in that case.