4
Now you're into some real fun.
Try changing your theme to the default, see if things get better then. If they do then invision board is messing with something on the screen display and causing various components to get shifted, misaligned, made ugly or whatever.
If you are not totally hung up on using invision board there are others that work well with xoops. If you want to see some you can go to
http://helpxoops.info. You can checkout newbbex (the one we use there...) also we have demos of Vanilla and smf. Use the Active Projects link to find things.
Have fun.