A lot of hands are not imported from Betfair. I remember I had this issue in the past also. When I played on William Hill there was a way to export chosen hands (that were not imported) hand by hand. There isn't that option on Betfair however. I use version 8454 (because I want to have hud on Microgaming). Is this Hm2 or Betfair issue?
edit. When looking closer the stats/results, I can see those are totally wrong. Example it shows I have played 2118 hands and paid $8097 rake this month (max rake can be $1/hand).
edit2. I created new database with version 8454. Same errors. Then I tried with version 8484 and it worked fine. Last month worked with 8454 but it seems ipoker have changed something that it doesn't work anymore.