Hi Ezy
If you have configured several ip ranges in same SVI interface using "secondary" keyword like:
interface ethx/y
ip addrexx a.a.a.a/z
ip address b.b.b.b/z secondary
ip address c.c.c.c/z secondary
Routing issues between these ranges will occur.
There is a bug: CSCtx11610
So the best would be to create separate vlans for each ip range and not use "secondary" address configuration.
Bug is fixed an fix will be commited to next NX-OS release.
HTH,
Alex