Need help with an old Addon (pvplog)

[Xaemyl]

This addon is pretty ancient, but it has mostly worked until the prepatch where it's been hit by the background/backdrop change with 9.0 (all the buttons and checkboxes are floating lol).

I can't wrap my head around it as I'm still learning all this stuff. If anyone could give some clues or point me in the right direction, the code is here: https://github.com/WoWRoster/pvplog

Thanks in advance!