how can I deal with it ?
Not every program is the same. Just because your video card can run League of Legends at 1350MHz, doesn't mean it won't crash if you try to run FurMark using the same settings. For everyone here having problems with crashes, blue screens, incorrect data, etc., TRY REDUCING YOUR OVERCLOCKS. It's not Claymore's job to 'fix his miner' because you refuse to find lower settings that work and tweak upwards from there. Also, every card is different. Just because one guy can copy 1375MHz memory straps and run at 2100MHz mem clock, doesn't mean that your card will be able to do the same. How about you try running 1375MHz straps at 1375MHz clock and see if it works first? If it does, that means THE PROBLEM IS YOUR OC.
EDIT: For people that want to mod your BIOS for higher speeds, just be aware that you need to test for stability and tune your speeds for the program you are using. It is a trial and error process and there is no cookie-cutter BIOS or OC settings that will "just work" for every card, in every program. That said, there is a lot of good info here:
http://www.overclock.net/f/67/amd-ati
http://www.overclock.net/t/1604567/polaris-bios-editing-rx480-rx470-rx460
http://www.overclock.net/t/1561372/hawaii-bios-editing-290-290x-295x2-390-390x
http://www.overclock.net/t/1561904/mlu-bios-builds-for-290x