Exactly the same thing here with my system fritzi. My home player wont play DVD+R unless they are booktype set to "-rom" but it will only play DVD+RW if it's not booktype set to -rom. Very weird.
The painful thing about this is that my burner (pioneer108) doesn't properly support bitsetting. With the standard firmware there is no bitsetting available but with the alternate "piodata" firmeware it always forces the booktype to "-rom", so I have no control over it.
So basically if I use the offical firmware it works ok for DVD+RW but I'm screwed for DVD+R, and if I use the alternate firmeware then I'm good for DVD+R media but screwed for DVD+RW. Yep I'm screwed either way.
Luckily DVD +RW seems to keep the booktype it was last set to during the last full format (or full erase). I dont use much +RW media but when I do buy some I just format it in a friends computer, one that will booktype it to +RW. Then I can leave my burner firmwared for perminent "-Rom" booktyping and my DVD+RW's still keep their +RW booktype even when burnt and erased in this burner. Just as long as I dont do a full erase in my burner then they will keep their +RW" booktype.
BTW. I think the differnce between erase and format is just semantics, different application programs use different terminology. The only things that are really different is full (format or erase) versus quick (format or erase). Quick erase only zeros the table of contents, that actual files aren't over-written. Full erase/format on the otherhand actually zeros the whole surface.