BMP180 graph not working properly

I added a BMP180 sensor on a RP model B (debian version Jessie installed)
When i show the graph it shows properly the last 10 minutes, the last hour, the last day, but when i ask to show last week it gives only 1 point and date shows 1 jan. On the graph of 1 month it only shows 2 points first and last.
When i show the graph in the webbrowser i can see the graph perfectly by showing in custom mode and select by date.
When I set the pressure unit to hPa, it shows no value anymore and I have to uninstall the sensor and reinstall it. I think here’s some bug…