Questions about reading and writing IPTC Tags

[D.Mon]

I have some questions about reading and writing IPTC Tags:

1.)
I have been writing IPTC Tags to some pictures from different camera models in the very same way (-CopyrightNotice='bla bla').
After importing those pictures to my image editor (still using Apple Aperture for my private stuff) I found that the CopyrightNotice tag was only displayed for images taken with my Sony camera but not for those that were taken with my daughters Canon camera.
Does anyone have an idea what the reason could be?

Edit: Now I can´t import -CopyrightNotice='bla bla' from files from my Sony cam either.
I did it yesterday and now it does not work anymore although I have taken the commands from the shell history 

2.)
I have a special german letter in my last name 'ß' (Klick).
I also use the ©-sign in my CopyrightNotice.
Writing and reading those characters with exiftool on the command line works.
In Aperture the © looks good but the 'ß' gets scrambled to 'fl'.
Is there anything I could do with exiftool to fix that or ist that a problem of the image software?

3.)
Is there any simple way to read (and write) custom IPTC tags without dealing with a config file?

[StarGeek]

No idea on question 1.   That just seems odd.

For question 2, you might check out FAQ #10, specifically the IPTC section.  You may have to set CodedCharacterSet when writing.

Alternatively, I'd suggest seeing if your software supports XMP.  Instead of writing to CopyrightNotice, write the copyright info to Rights and see if Aperture displays it correctly.

3, AFAIK, no.