yup copy the 3 lines of your public addess from the PDF offline wallet to notepad and merge them into one line - no spaces...
this would be your proper public address to use in a mining pool
ex:
public key on the offline wallet pdf is :
aaaaaaa
bbbbbbb
cccccccc

public key to use in mining (or receiving in general) : aaaaaaabbbbbbbcccccccc
hope this helps!