O.K., the first thing is that you probably did not move your "iPhoto Library" to the external, you probably just moved some of the files. That is the first mistake. You can't just drag and drop photo files and have it work properly afterward. The whole iPhoto library should have been moved, but that is water under the bridge now.
The first thing I would do is to try a rebuild. See the instructions here:
http://support.apple.com/kb/HT2638
Try that and report back. Maybe someone else will have some suggestions for you in the meantime.