In the newest release 1.4.4 there is a problem with supplements when booking:

instead of showing the booked supplements there is only shown the phrase List supplement free

Object: Haibike Speed RC / Price / Day
Reservation Date: 2012-09-27 - 2012-09-29
Quantity: 1
Price: 72 Eur
Deposit: 100 Eur
Framesize: List supplement free
Pedalsystem: List supplement free

Also in confirmationmail to customer and when reviewing the booking on the site.
But it's written correctly to the database

Problem solved - was incomplete Languagefiles.
My Languagefilse are stil incomplete but I'll post them when they are in a useful state.