Oscilator: Mine: Crystal 8+, Yours Full Swing
Boot flash size: Mine: 512 words, Yours 1024 words
Brownout: Mine: 4.3v, Yours 2.7v
I have CKSEL3 on, yours off
I have BOOTSZ1 on, yours off
First three definately not related - checking datasheet re CKSEL3 (Clock source)
Peter