Mirror paste messing up my characters feet!

I am trying to use mirror pasting to help me animate this character.

This is him in the correct contact position

but this is what happens when I mirror paste:

Any ideas what could be causing this problem?

It looks like it’s mirroring along y rather than X. Is it possible you built your character facing X rather than Y?

no he’s on the y axis. I’ve just tried rotating the spine bone 180 but the problem remains