i figured it out, what was the problem. it was my spaun disecq switch!!!
but why did it work with my dreambox and/or softwarelike progdvb? only mediaportal made problems with it.
now i use a cheap disecq switch und everything works fine
the solution, i posted is not correct. because i had the same problem yesterday again. unable to scan....
now i figured something out. i have to connect the sat cable to my dreambox and let in there for a few hours and switch some channels. after plugging back the cable to my tv card, everything works again.
There is one more idea. Karill what satellite you recieve?
The request to all at whom the same problem to replace contents of a file with the name of your satellite in a folder "C:\Program Files\Team MediaPortal\MediaPortal TV Server\TuningParameters" on contents of a file from the attachment archive. If your card is capable to accept S2 also to replace all the text "S2" on "8psk", restart tvservice and to repeat scanning.