Sorry for the delay in the reply Laker, I didn't see your reply, my bad.
Okay, in the vBulletin Options, you can reduce the height and width of the area where the like box appears, that will reduce some of the whiteness and also it'll reduce the height of your postbit too, looks like it's currently being vertically stretched by the mod.
Facebook only provides two options; colorscheme=dark and colorscheme=light - so I have to add a colour option to the mod in the vBulletin Options where you can set a background colour. I'll do this and add it as an attachment to this post as soon as I can.
Also, I would start advising your members to stop using IE, it's very behind on web standards and such, not everything works correctly in that browser.