dvd+r on Roadstar_problem

[monthi]

I have a Roadstar dvd-2020h dvd player. My problem is the following:

I have a dvd+r disk written with 2 speed. When i insert it into my dvd player it says "no disk". What can be the problem?
I havent manage to play any recorded dvd. I can play only original dvd films.
According to compatibility list my player would play dvd+r.

Please help me,
Thanks

[tompika]

Burner, firmware, software, settings, media????