FIR Compiler v8.0 interpolate by 2 FIR is broken

Attached are some plots comparing FIR Compiler v8.0 and FIR Compiler v3.3.1 interpolate by 2 FIRs.

Has anyone else seen this problem? Has anyone successfully generated interpolation FIRs with FIR Compiler v9.0?

From the latest MegaCore IP release notes and errata:

Incorrect Results for Multi-Bit Serial or Interpolation with Signed Binary Fractional

Incorrect results when Structure is set to Distributed Arithmetic: Multi-Bit Serial

Filter or the Rate Specification is set to Interpolation, and Signed Binary Fractional

is specified for the data type.

Simulation Result Incorrect Using MCV Interpolation Filters

Some multicycle variable interpolation filters with high interpolation factors may

generate incorrect output.

Incorrect Output for Signed Binary Fractional Multi-Bit Serial or Interpolation Filter

The FIR Compiler output data is incorrect if you choose Signed Binary Fractional

data type with Multi-Bit Serial Filter structure or Interpolation rate specification.

No mention of problems with signed binary and low interpolation factors, so I suspect the problem will be present in FIR Compiler v9.0 also.