LO 7.0 strange behaviour

Hi,

Im using LO 7.0 mainy with calc on a debian jessie. I update LO about 
2-3 days.  Calc jobs are aved as .xlsx file since my colleagues use Windows

The strange behaviour is

I work with calc and everything is ok, then save and quit

Next time I start calc it happens, really often, that the top side is 
out of screen. Exit with ctrl-Q and rerun. The same position. If I use 
killall soffice.bin the rerun calc, the "tool" is where its supposed to be.

I noticed its tied up to each xlsx file. I mean: after the succesful 
rerun of a.xlsx I open b.xlsx but the top side is off the screen. 
Killall soffice.bin, rerun both a and b and they are ok. But if I open 
c.xlsx the problem is still there.

Any hint?

Thank you

paps