The only "quality" brand in my place is Ritek. What's going on with Ritek "-"? The quality is degrading like fading dye when not use immediately, CRC erros in a few months after burning. And you should keep them in a air-tight place. So I'm using "+". I'm talking about Ritekg04 -R 4x and ritekg02 +R 4x.

Not with you? air tight casing? dye degrading? Ritek has been hit and miss over the past year or so, i use Ritek G05 8X -R sold as Traxdata and theyve been great just go for an official ritek brand and you should 'should' be ok , however your liteon i take it its a 451s right? will prefer +R

I'm not sure where you're pulling your crackpot MIDs from, but here is the reality of Ritek MIDs:
Ritek 4x DVD-R = RITEKG04 or RITEKM02
Ritek 8x DVD-R = RITEKG05
Ritek 4x DVD+R = RITEKR02
Ritek 8x DVD+R = RITEKR03 (revision 01 or 02)
Ritek 16x DVD+R = RITEKR04

I thought that some of the 4x Ritek DVD+Rs were RicohJPNR01.

Yep, you're right. You can find RICOHJPNR01 in some 4x Ritek DVD+R packages.
I was referring to Riteks' own inhouse developed discs and MIDs.
RICOHJPNR01 = Ricoh technology, but manufactured by Ritek.