CCSv5.1.1 ioport not working

I just upgraded to CCSv5.1.1 from CCSv4.

In my code, I have a bunch of lines that look like this:
volatile ioport uint16_t * ACS2CR1 = (volatile uint16_t *) 0x1010;

Those now get flagged as syntax errors by the Eclipse CDT parser (see this post).

However, it seems that in my CCSv5.1.1, it ALSO gives me compile errors when I try to use that variable. Therefore, I can't build.

Error: Symbol 'ACS2CR1' could not be resolved
Type: Semantic Error

That error occurs on this line:
*ACS2CR1 = 0x0501;