IPhoto has detected inconsistencies in your library, multiple iPhoto users

Question

We have a MBAir with OS X 10.8.4.
We are two users of the same computer with 2 different user profiles. Our user profiles, imessage - facetime accounts, even system languages are different.
However, we want to use the same iPhoto library, therefore I've created a diskimage and had both users' iphoto addressed to the same iPhoto library which works. Both users can make changes in the iphoto library and the other user will see the last updated version when he logs in.
...however, we come up with 2 error messages. Not always, but very frequently.
1- "iPhoto has detected inconsistencies in your library.
Please click repair to avoid any potantial problems."
When I received htis error message, I clicked repair for a couple of times, but the error message comes up again and the repair takes very very long time. So I don't click repair button anymore. I don't know what it repairs.
2- "Insufficient disk space, iphoto cannot import your photos... "
This error may appear 1 time and when I click o.k. it just disappears and I can work on iPhoto as I want.
Sometimes, it keeps nagging 3-5 times and then dissappears after clicking O.K. everytime.
And sometimes it keeps appearing endlessly, every time after clicking o.k.
MBA has 512 GB storage where 300 GB is empty, so there is sufficient disk space, that's for sure.
I can imagine that this problem probably occurs because both accounts have its own PhotoStream linked to iPhoto (from mobile devices) ,and both accounts keep importing the Photo stream photos but I'm sure that there should be a fix to it.
I'd really appreciate if anyone could help, it's quite frustrating. 

Answer 1

Where is the disk image located?  How big is the library as reported by the Finder? Although using a disk image is one of the methods suggested for sharing a library between users on the same Mac, it's been a problem for many.   How much free space do you have in the disk image.
I'm thinking this workaround would work better for you: partiton the HD to give a volume just for the library that both user accounts can access. Set it to have enought room for your library to grow.  But don't let your boot volume go betlow 10-15 GB free space.
Have that library volume set as shown below and to ignore ownership:
Are both users have their own iCloud account or are they using the same account?  I would think it would have to be the same account because a library can only sync to one account. Therefore I don't think the PS syncing would be involved.
Another option would be to use an external HD.  Some are as small as a mouse:  OWC Mercury On-The-Go Pro USB 3.0 & 2.0 / FireWire 800, and 2.5" SATA Portable External Hard Drive & SSD and are powered by the Mac.
OT