coolbook reads the smbios file in extra so you have to use a compatible smbios identifier like macbookair1,1 or macbook2,1. there are more supported identifiers but you would have to compare the ones that coolbook can use to a smbios thats more compatible for your specific hardware like graphics and cpu class (yohan,merom,penryn,etc...)
so you can try changing smbios identifier using lizard app and try changing it to macbookair1,1 at least it uses x3100 graphics