HP50G help as POP command —> insufficient memory

[Gil]

With HP50G EMU48
I used many times PUSH and POP commands.

Always with no problem.

Then I did something wrong, but I don't know what.

When I execute now a program with PUSH (or when simply pressing PUSH), then I press POP and get the message 'POP Error : insufficient memory' and fall into the directory CASDIR.

Then I tried and deleted a lot of directories.

From the command line I execute a PUSH command.

But, after execution of POP, I always the same MESSAGE and "arrival" at CASDIR directory.

How can I reinitialize the PUSH/POP memory?

Thanks in advance for your help.

Regards,
Gil