Private Equity Manager reports that with regulators looking over their shoulders, some GPs are playing it safe by hiring third-party valuation advisors to check their numbers. However not all third-party opinions are equal, warns Cindy Ma, managing director at advisory-focused investment bank Houlihan Lokey.  PE Manager’s Nicholas Donato talked with her recently.  Here are excerpts:  There was a feeling of unease in the industry when the US Securities & Exchange Commission (SEC) announced an informal inquiry into private equity portfolio valuations. Many wonder, how do I stay off regulators’ radar screen? The SEC has developed a number of analytical tools that now…