AIX secondary shell problem with newer MC

[Alexander Varakin]

I have compiled mc 4.5.51 some time back on AIX 4.3.3 and it works, except
one very important feature:
when I close the frames using Control-O, I don't get a proper secondary
shell (I see only $ prompt and  I can't run commands from there).
My friend compiled the latest MC, but he also has the same problem.
Even the mc which comes with IBM's AIX Linux toolbox has the same problem.
In the older version 4.1.?  this feature works well.
Any ideas?

Thanks,
Alex