3d array acces bug

Hello!

I declared 3d array in my Keil project for lpc1788: volatile uint16_t db[16][128][3]. When I read members of the array db[x][y][z] with z < 1 there is no problem. But if I try to read members with z >=1 I always get 0xFFFF, even if they are not equal 0xFFFF (I checked it in debugger). For example:

db[0][1][0] = 0x1515;
uint16_t id_ = db[0][1][0];       //works fine, id_ is equal 0x1515

db[1][0][1] = 0x1515;
uint16_t index_ = db[1][0][1];    //returns index_ equal 0xFFFF

Could anybody explain to me what's wrong?

Regars, Vasilij.