Edit: AMD 14.6beta is behaving strangely with me after I tested for hours, it is the issue:
Whatever I tried to change the GPU/Memory frequencies, it is still the default (factory) values, whether I tried it via MSI after burner or via the miner's conf. file, though GPU-Z shows that the frequencies had been modified, but in fact the REAL ACTIVE values are the factory's one, and the hashrate had not been changed what so ever.
I dont' know is it me or is it the driver.
I downloaded AMD14.4 driver, tested it. I confirm it is working perfectly, the performance is the same of 14.6beta PLUS you can play with the frequencies.Ok,i got 4.4 on 280x but pool doesn't see that....

What's the difference between the miner's hashrate readings and the pool's hashrate readings for your card?
Have you tried it too with another pool?
5xxx and 6xxx ?
can it support 5 & 6 series amd cards?
If i will be able to add it i will do it ASAP, but give it a try
thanks kozmos
would you mind to share settings for your cards (7950 & 280x) please
Sure, here it is:
http://pastebin.com/4vS1gw8e
What about heat and wattage? How're they in comparison?
GREAT JOB !! Will test ASAP
wow, that's a huge improvement! Excellent JOB!
Heat is the same

I can not confirm the power consumption cause I did not measure it, but I believe it is the same mostly cause there is no major change in the temperature.
You are welcome guys, the biggest credit goes to djm34.
I re-complied the sgminer and fixed a consistent (idle/work resuming) issue within the mining process.
thanks, but the speed on 290 and 290x is not increase in this (idle/work resuming) fix, please recheck
I guess someone else faced the same problem, check this out:
https://bitcointalk.org/index.php?topic=623409.msg7406963#msg7406963 This issue lies with MSI afterburner...
(actually I had that problem since some time and it isn't limited at all to 14.6 and was stuck for some time at 1080 which isn't my factory clock).
No get past that, you need to kill msi ab and restart it (or restart the computer before)
Considering the speed increase, you lose it if you don't use 14.6 (although, there were some report it was possible to use bin file generated in 14.6 in older version of the driver.