I just finished installing both mantis, wonderful program. Have 6 test bugs in the system, everything seems to be working fine except one chart - summary of problems by date.
It lists the number 6 straight down the list from 1 to 365, and it hasn't changed over the last two days.
The chart graphs the number of bugs that were submitted less than or equal to n days ago, where n is the number listed in the right hand column. If you added 6 bugs on one day, all of the numbers would be the same until after the 7th day.