XFwm Compositor does not like work well with Image Magick import command

[Patrick]

I have xfwm4.4.2, Image Magick 6.3.8.3, and nvidia driver 169.09.

With the compositor turned on, I used import to take a screen shot:

import -window root screencap.png

This completely stalled the computer for about a minute, after which
it did finally did produce a screen shot. If I turn the compositor off
the import command is near instant, as usual.

Has anyone else stumbled across this? I couldn't even ssh into the
computer while it was happening :(. I am not a programmer and I have
no idea what may cause this. If I can should provide any more
information just let me know. Thank you.

Patrick