Upgrade 0.6.9-0.6.10 smooth on Win 7 64 bit. Good job!
A couple of points for the Report tab, number of days section:
1. The dates that are not entered yet (ex: not yet harvested/cured) are defaulted 01/01/1901. I think it looks cleaner and more consistent if you leave those blank, as you have in the Plants tab "info" area.
2. I suggest changing "Veg Start" to "Veg Time" (or Veg Period) and change the logic to calculate it. When I am in flowering, I care more about how long I vegged this plant for, rather than how long ago I started vegging. I'm in flower after all... Also, from a historic point of view it is an important number, i.e. I vegged this plant for so many days and it got that tall and yielded this much, etc... Currently, I have to do a manual calculation to figure out how long each plant was vegged for. I am not sure if you have the same logic for the other stages that always compares the start date of a stage to today's date. I think this has little value if I'm looking at a plant that I grew out a year ago. What do you think?