Profile Milling accuracy

[Garban]

We recently purchased a used Toyoda FA550 II with a 15M control. The machine has been working great except for profile milling accuracy. It's rounding off corners and making sloppy blends into arcs at all feed rates. It does improve slightly at lower feed rates under 40.0 IPM. The only thing that helps is using a G9 at the end of every finish pass line of code which causes a noticeable dwell mark and high cycle time. G62 doesn't help and G61 does the same as G9 but modal. Hole position accuracy is excellent (positional 0.003 over 11 inches). The company we purchased it from never did precision profile milling, only face milling and precision holes. Is there a parameter that controls X/Y axis accuracy during milling only? Any suggestions would be greatly appreciated! Thanks in advance.