iPhoto hiccup (1 Viewer)

hihiccup hi I had a wierd happening last night whilst using IPhoto 11 where the screen flickered a few times but stabilised. However when I turned the computer back on this morning there are two empty folders. On the screen which I can only describe as outside the IPhoto on the Initial start up screen. When I try to place them in the trash a drop down box appears stating I need to use my password which I duly do then another dropdwnbox appears stating I do not have the authority??? Then I checked my admin credentials all is well. I currently have 2300 photos in the IPhoto. is there a limit as to how many photos I store in IPhoto? The IMac is 6 months old and the 1TB model ? Any help will be very much appreciated as to removing these album folders. Regards. Mike