uint8_t to uint32_t pointer cast with arm-none-eabi

I encountered another problem when I moved from arm-elf- to 
arm-none-eabi-
The following code:

uint8_t *Data;
uint8_t  Idx;

*((uint32_t *)(Data+(6+Idx)))

would not work anymore.
My intention was to fetch 4 bytes pointed by Data (plus 6+Idx)
and interpret them as a 32-bit unsigned integer. It worked with arm-elf 
but with arm-none-eabi only the lowest byte of the resulting 32-bit word 
was correct. Could anybody help ?

Pawel.