GA-MA790XT-UD4P Keeps loseing hdd's/dvd

Need way more detail to help:
what's hooked up to which port?
All SATA, mixed IDE/SATA?
Power supply - what is powering the drives - modular?
Single rail w/SATA connectors? Any MOLEX? Molex to SATA adaptors?

Here's the specs mate thanks for your help. No molex adaptors

cpu Phenom II X3 720 Black Edition
mb GA-MA790XT-UD4P
memory 4 gig kingston hyper x
hdd 2x seagate sata
hdd 1 hitachi sata
hdd 1.5TB Samsung Spinpoint F2 sata
dvd sony AD-7240S sata
gpu xfx 4870 1 gig
psu jeantech 700W Storm modular

First thing to check: modulars, while excellent for cable routing and maximizing airflow by 'tailoring' the cable setup, are prone to a common weakness - the modular connector at the PSU itself. In the 'sticky', I mention troubles with the MOLEX to SATA adapters, where 'twisting' 'em one way will be fine, but a slightly different direction (or worse, when they 'relax' into a different position after some time...) makes 'em 'drop out'... With the mods, the main plug can suffer the same syndrome. Its almost never the actual pins on the PSU; when you look into the end of a mod plug, you will see a series of little brass 'cylinders' that 'wrap aroung' the PSU's pin, to make the contact. If one of these cylinders is not properly formed, or opened slightly, you will wind up with an intermittent. You want to either check the power delivery to the SATA plugs with a meter while 'wiggling' the modular PSU connector itself, or use a jeweler's screwdriver to bend any suspect ones slightly 'in' toward the center - this will give you a better 'clamp' on the pin itself. There's a pointer at the bottom of the 'sticky' the explains how to turn on the PSU for testing, if you select the 'meter' route...

If you read through a bunch of modular reviews at JohnnyGuru, you will see that this is the main complaint about mods in general - even so, I'd never use anything else, now that I've seen how all-round convenient and functional they are - looking at a 1500W for the next workstation rebuild!