PCC validity ?

[jes_ON]

It seems that my understanding was totally wrong;
does that mean if someone gets PCC; & after 2 months that person applies to CIO, Canada. Once application is approved say after 2 months; and asked to submit full doc in 120 days (4 months) & full doc are submitted after 3 months of this instruction;
if those PCC are submitted after 2 + 2 + 3 = 7 month
those PCC are valid since those PCC were issued 2 month before initial application to CIO, Canada?

Yes.

See p. 20 of the instruction guide:
http://www.cic.gc.ca/english/pdf/kits/guides/EG7.pdf

"You may begin to gather your police certificates before submitting your application to the CIO. Although you will not submit the police certificate to the CIO, you must be ready to submit them to a visa office if your application is recommended for further assessment at a Canadian visa office. When you submit the application to the visa office please ensure that your certificates were not issued more than three months before you submitted your application to the CIO."