I am not sure what you are trying to do, but I were to clean the whole lot and leave only lets say only 28.2 east on there I would do the following:
Make a backup of your dreambox with FWP , just in case
1) Open your settings with dreamboxedit.
2) Sort the stations by sat position, make sure to have select "all types" and "all satellites"
3) Mark all stations from -45° to 19 east and delete. That might take a few minutes. Then repeat for the sats from 28 onwards.
4) Then you could go to the right side of the screen where the buquets are (Buckets in English
), right click on TV user buquets and "remove empty". Remove anything else you don't need anymore.
5) Then comes the important bit: Go to "tools" on the top menu, first click "Update satellites.xml" and after that "clear" - that will leave you with a simple and clean satellites.xml.
6) Important: Safe the new set "save as" in a new location.
7) Send the lot back to the dreambox, make sure to have the "remove unused buquets" option on, otherwise you'll be left with garbage. Press reload setings on dreambox.
8) Go to the service searching, satellite configuration, and set it to single sat 28.2. Reboot the dreambox.
After reboot you will find it all clean and tidy.
Even if you go now and change it back into "Diseqc" it will only have one sat on there.
Hope this helps
