Turntable adjustment


I've recently acquired a Technics SL-QD33 turntable with a p-mount cartridge. Anti-skate is factory set and non adjustable. Also, its fully automatic. Everything worked fine with the stock cartridge, but I wanted to upgrade so I purchased the Grado Prestige Green cartridge, which has improved the sound.  However, now when I start to play an album, the tone arm no longer places the stylus in the groove, thus, it slides off the record. What can be done to address this issue? 
hawk28