How can I merge multiple iPhoto libraries?

Thus far, I tired

1) Exporting "Events" from one iPhoto library to the desktop, and then imported them into my desired library. The problem was when using the iPhoto export feature, the videos don’t get exported.

2) When dragging "Events" into a new folder on my desktop, and then importing into desired library, the time adjustments I made to my files to not make the transfer (the files do - but not the time stamp). You see, I have many files where time adjustments were needed. I used the very useful "adjust time and date" feature in iPhoto to make my adjustments. My files are now properly adjusted to their proper time - I don't want to lose that information.

3) Lastly, I saw many people mention on the discussion board a third party software called "iPhoto Library Manager." This program works just as good as dragging a library to the desktop (or external drive) and then importing files into desired library - it was not able to properly transfer the adjusted dates (so that doesn't work either).

I greatly appreciate your suggestions.