Iam still on PHP 4.3.4 and would like to upgrade to 4.3.6.
I see in Apache upgrade that 4.3.6. is marked as TESTING. What this means?
I would like to hear from others how you comment this upgrade

and when upgrading PHP through WHM option of Apache update, do I have to select everything I had before or I can just select PHP (with other defaults already selected) for update and nothing from previous selection would be removed ?

I have upgraded PHP to v4.3.6 on two machines, one RedHat 9 and the other RedHat Enterprise 3. So far I've not had any problems with it.

Testing probably indicates that it is still in the testing stage and not actually ready for production.

Maybe so, but I noticed they had the same "TESTING" notice for v2.3.5 until v2.3.6 came out then only that one had it.