Inaccurate Data

I am having these issues...

At the time of reporting several weeks using Timesheet by Project and Memebrs reporting feature, my reports does not show all the weeks checked off by my boss. His reporting does but not mine, both are based on the same underlying data. Why is that?
The timesheets for certain employees seem to go blank at times and suddenly the data appears weeks later. What's going on?

Thanks for helping.