Problems with DVDRW discs and standalone recorder

i have got 25 new discs verbatim dvd-rw 4.7gb go 4xspeed vitesse 120 unit is a funai dvd recorder is old but has done very little.i have also got some maxell 4.7 speed2x dvd rw.the 25 new ones will not record it just tells me disc error ccan not record but the maxwell ones are allright i am not very good with these things have i got wrong discs please could you help.

Your standalone cannot deal with 4X DVD-RW media, simple.