Hi everyone, I got a 2011 128GB i5 11" MBA (samsung SSD). I didn't want to pay £250 for the upgrade to 256GB, so I managed to get a 256GB (toshiba SSD) 2010 MBA from ebay for a good price. My plan was to switch the SSD and then sell the 2010 on for a minor loss. I opened both machines, everything went smoothly with the 2010 MBA. The 128GB ssd was fine, booted from USB stick with Lion on and began installing Lion no problems. The 11" however is being troublesome. The 256GB SSD had a fresh install of Lion on, however it wouldn't boot from it. So I tried booting from the recovery HD. It wouldn't do it- the grey apple appears then turns into a 'no entry' sign, and then it turns off. I swapped the SSD's back, and had the same problem booting from the USB on the 2011 (no entry). I then instead selected the recovery partition and that has worked. It seems that my 2011 with only work with the sad it shipped with So in short, with the 256GB in the 2011, I cannot get past the apple sign whatever I do. All that i've managed to do is a hardware test and that says there are no problems. Anyone have any ideas or solutions as to why the 256GB causes issues? Any help would be greatly appreciated.