Toshiba Regza 32RV635DB EPG problem

Hi all. I just bought a Toshiba Regza 32RV635DB for my wife - both very pleased with it - but one oddity; to check the sound, we tried 703 (radio 3, passable) & went back to TV channels. When she later scrolled through the EPG, it looped to 310 & returned to 1. However, entering 703 gave radio 3 again. She found that by entering 700 she could scroll in a loop 700-730ish.
It's annoying, 'cause you don't what other channels you may be unaware of! Anybody else noticed this?