Looks like you'd like a different answer than the one you've already been given in another post.
The NIOS data master is 32-bits wide and it isn't going to get any bigger. Now the avalon interconnect fabric will handle adaptation between the NIOS' 32-bit master and your 128-bit slave. However, the way it does this is it addresses a portion of your 128-bit bus with each access. If you don't provide byte enables, each time the NIOS performs a 32-bit write to your slave, 96 of the 128 bits will get written with bogus data.
The solution is to add byteenables to your slave.
Jake