Button dispalyed on ajax pager click

If i install the calendar module (and date, views, etc, etc) and install scroll to top, navigate to the calendar page display (month) click on the calendar pager to jump to the next month, the scroll to top button is rendered and wont hide again / stays on a fixed position. I don't know if this is a calendar or scroll to top issue and back to top has a similar issue, but i guess i try here first. (and im not that strong on javascript, php / perl are my choices in life, else i would have tried to fix it myself)