How were you trying to add the photos to the journal?
To edit an iPhoto journal you need to open the journal on exactly the iPad that created the album, signed into the iCloud account used to publish the journal.
See the iPhoto help: http://help.apple.com/iphoto/ipad/1.1/#blnk22fd2407
Add photos or video clips to a journal:
After you create a journal, you can add photos and video clips to it at any time.
Add photos or video clips to an existing journal
- Tap a photo, video clip, album, or event and tap
> Journal.
- Confirm or change the photos you want to add:
- Select all the photos in an album or event: Tap All.
- Select a range of photos: Tap Choose Photos, tap Range, tap the first and last photos in the range, and tap Next.
- Tap Journal and tap the journal name.
- To add the photo or video clip to a specific page, tap Page, tap a page name, and tap Add to Journal.
- Add photos to a page with other photos from the same day: Tap Automatic.
- Add a page name to the new journal page: Tap New Page.
- Do one of the following:
- Return to your photos: Tap Done.
- View the photos or video clips you added to your journal: Tap Show.
If don’t see your added photo or video clip, swipe to navigate between journal pages.
Regards
Léonie