I have exactly the same problem... I always get the "don't meet requirement" dialog while I actually have an empty 6 GB space... If I continue to try to make partition, in the end I'll get error message "OPEN DISK READ-ONLY - YOU HAVE NO PERMITION TO WRITE"... and then... "FATAL ERROR CANNOT GET DISK SIZE".....

can someone help with this problem, cause I'm new to Linux and seems that I won't be able to solve this although I've spent like the whole day... =(