It doesn't seem to effect the functionality but it's weird.  I duplicated it on two different computers running OS X 10.9 and v0.8.5-beta.

When using the importprivkey command when the command completes the success message is blank, there is just an icon with a blank line.

After completion the key you just imported shows up in your address book (i.e. like an outgoing address) instead of under receive as incoming address.  The coins still show up in your balance but the address is on the wrong screen.  When you restart the program this corrects itself.