Iphoto 11 spinning balls when viewing photos

Question

Hi - We're pretty frustrated so seeking help here as iPhoto support via Apple Care has not offered a solution to our issue. We have late 2012 iMac 8mb RAM with 3.2 (or 3.4) processor.
We have 3 Nikon cameras; D80, D300S, D800.
The D800 is the newest.
Uploading from cameras into iPhoto works perfectly.
However, when viewing a particular Album that contains photos from all 3 cameras, we get spinning ball and have to wait for up to 30 seconds to go from one photo to another
The spinning ball is random BUT doesn't happen on D80 or D300S photos. Only happens on D800 photos, which makes us wonder if there is a bug in iPhoto. The D800 is supported in iPhoto.
More info: The size of the photo doesn't seem to matter, as this can happen when one is going from a large MB photo to a small one, and visa versa. It doesn't hang on particular photos, but seems to be random.
The D800 is a 35 megapixel camera if that info helps at all. The other cameras are much lower megapixels.
I don't know enough about computers to solve this myself, but iphoto support has not found the problem. I think it's a lot simplier than we think but don't know what to do next.
Apple Care iPhone support had us repair the library and even make a new iPhoto library but we got the same issue.
The album with the issue contains 173 photos, so of which are HDR. It is not getting stuck on HDR photos, but sometimes it can. Like I said, it's random.
When we put that same album into Elements12, there was no issue of spinning balls, so I also wonder if it's the size of the entire library that has something to do with this issue. (the iPhono Library contains 5,000 photos. Support confirmed that there is plenty of free memory so that is not the issue either, but we are going to have the 8mb upgraded to 16MB anyway but we don't believe this will solve anything at this point.
We really wanted to buy Aperture but wonder if we need to resolve this issue in iPhoto first....Thank you  & I hope I provided enough info. I tried...-Lynn

Answer 1

Yes, occurs in both RAW & JPEG
Here's what we learned today: when we call up the Album in question (but does happen in other albums but trying to stick with just one for now) it is now confirmed that it's only happening with D800 photos,but doesn't matter the size of photo or whether Jpeg or Raw. Can be either/or.
BUT, once we go thru the entire album of 174 photos, the time lag is gone the second time we view the photos. (no spinning balls & can scroll rapidly thru entire album) Wouldn't this suggest not a camera issue?
If we close out of iPhoto and go back into iPhoto and to that same album, we get the spinning ball delay between some of the D800 photos as before, but also confirm that it doesn't hang up on same photos each time but hangs only on D800 photos.
One more thing that may mean nothing - The abum has 174 photos. The first 100 or so photos were shot with the D80, the next group are D300s, and the last bunch (from photo #145 to 174) are D800, so the hanging doesn't begin until #145, but might not hang until photo 150. It's random, and different each time the album is opened AFTER iPhoto is closed & re-opened. As long as the album remains opened we can even go to other albums & go back to that album & all is still fine. It's just the intial opening of iPhoto each time.
This particular album IS a "rated" album so it has that cog wheel on the album file. Because it contains all photos that my husband rated as "3-star photos", I thought maybe the "smartness" could be the issue, but he has other albums with D800 photos that aren't rated & those photos can also hang...
Hubby has gone out to shoot post-blizzard photos & we'll do as you suggested upon his return & make new iPhoto library! Thanks! Will report back!
Lynn