How close was Leon Panetta to the Institute for Policy Studies?

Leon Panetta - Barack Obama's choice to be director of the CIA - supposedly had/has links to or perhaps even membership in the radical Institute for Policy Studies, an alleged Communist front organization. However, a search fails to turn up much beyond noise. If anyone has credible information - such as with contemporaneous news reports or IPS literature - please leave a comment.

More on IPS here and here (1977 Heritage Foundation report), supposed Clinton links here (also here)

And, this page prefaces a list including Panetta with this:

Congressional supporters of the IPS have included many of those who biennially commissioned IPS to produce an "Alternative" Budget that dramatically cuts defense spending while increasing spending for social welfare to levels only dreamed of by Karl Marx.

And, a comment here says:

Leon Panetta was included on the masthead of this front group [IPS] even while he worked in the White House

UPDATE: From this:

In April 1985 Panetta joined with 13 of his leftist congressional colleagues — including Ron Dellums, Don Edwards, George Miller, Christopher Dodd, and Les Aspin — in sponsoring a 20th anniversary fund-raising gala for the pro-Marxist Institute for Policy Studies (IPS), which had been described by Brian Crozier, director of the London Institute for the Study of Conflict, as the "perfect intellectual front for Soviet activities which would be resisted if they were to originate openly from the KGB." The IPS was originally funded with millions of dollars from the Faberge perfume magnate and Communist Party member Samuel Rubin and his wife.