Global Variables and debugging

I am using a system with a NIOS II/f and a level III debugger.

I am writing a simple (C) program and I am running the code and data from 32K bytes on on chip ram for testing purposes.

The program contains a two dimensional array.

init[4][256]

The array is updated with predictable values on an interrupt.

When I look at the global variable init[2][0...99] in the variables pane the data is incorrect.

However I then get the address of init[2][0] and look at memory and the data appears correct in here. Therefore the memory pane differs from the global variable data.

The data at init[0][0....255] and init[1][0...255] appears ok (although this data is never overwritten, only the data in init[2][0....255] and init[3][0....255] appears incorrect and this is the data that is updated on the interrupt).

And advice or suggestions as to why this is happening?