Can't access local X server after GNU Screen started from X-forwarded ssh session

[MercuryShadow]

I end up taking a lot of work home with me (unfortunately), and as a result I use GNU Screen heavily so that I can VPN in and resume work where I left off once I get home. I use X forwarding to forward my display from my work box to my laptop for the occasional times that I need it, but when I start GNU Screen from an X-forwarded ssh session, then detach from that screen session, I am unable to access the local X display when I go back to my work box and resume the screen session:

ejohnson@dfwejohnson:~$ nautilus . &
[1] 4708
ejohnson@dfwejohnson:~$ Could not parse arguments: Cannot open display:
^C
[1]+  Exit 1                  nautilus .

I did some googling and found a recommendation to run xauth merge ~/.Xauthority but this did not solve the problem.

Any ideas?