There are a few possibilities. There's a version 1.1 of this game. The main executable is different, so if you have that, the routines may not be in the same place. And another is that the GS Lite for the PS1 doesn't support the "D" code type, but in most cases the cheat device would just ignore commands it can't handle and process those it can.
When you say GS Lite, I hope you're referring to the PSX cheat disc. If it's a PS2 device, you can't use PSX codes with it.
And lastly, it's always possible that you entered something incorrectly, or if the game requires a Master code on that device, you don't have it.