Note: my original version of 5.1.570.0 is completely wrong - please ignore that. I was looking at the version in an early 6.01 build.
Regardless, the issue is that after the emulation update, step over stops working. I've opened SDSCM00050386 to track this issue. In the meantime, if you've already installed the emulation update, you can work around it by patching the disassemble_ank.dll file located in ccsv6\ccs_base\emulation\tpi with the version attached to this post.
Darian