Can we get some more info on your hardware?
To start looking for your RAM issues we'll need more details.
The Asrock motherboard site lists these
MOBOs for the 1156 socket. Can you clarify which MOBO you have?
Which i5 CPU?
Do you have the p/n for the ripjaws RAM?
RAM testing is the process of trying to find bad RAM sticks and bad RAM slots, it is very important to test the RAM in different slots. If you ran the test for both RAM sticks in the same slot, then we have not determined the integrity of the slots.
When you ran the memtest86, which sockets did you have the RAM in?
Which drivers have you updated?
What BIOS version are you using?
Did you update the chipset drivers?
Are you using AHCI or IDE settings in BIOS?
Are the BIOS settings for RAM at default or have you changed them?
The default settings for the RAM are usually low settings to keep from damaging your RAM, this may cause problems as you've seen.
This is a lot of questions to answer but these will help to narrow down the possible causes.