The following steps should resolve this issue:

1. Quit SOHO Organizer is it is running.

2. Open the following directory on your computer:

~/Library/Caches/MetaData/

Where '~' denotes your home folder.

3. Delete the 'SOHO Organizer' folder in the MetaData directory.

4. Launch SOHO Organizer.

5. Wait three or four minutes while Spotlight indexes the contacts and calendars in your database.

6. Perform a search in SOHO Organizer.