try using this command :

manual says :
ph_setcorrections (var ERP, var CFM);
ERP Error Reduction Parameter [0..100000], default: 20000
CFM Constraint Force Mixing [0..100000], default: 0.1

i would suggest using something like this : ph_setcorrections(8000,0.001);

also try setting ph_iterations
the higher the value the more accurate the physics will be.

but i think ph_iterations was not implemented in 6.22.0 tough ...it would be better to update to the latest version, physics are faster there