Hi Ben, it is generally recommended that B/C be avoided on colour image editing and on global edits. Unlike levels/curves - all tonal levels are equally affected by the edit, often at the expense of highlights and shadows. It is more useful on alpha channel data or maskig than for global colour edits. Try levels or curves, but if it works for you then don't change just for me. <g>
Are you using masks or history brush to paint in the local corrections of the global correction, as I take it that the whole image is not suffering and only certain places?
Try the dodge tool, there are may methods.
You could add a new blank layer set to overlay mode and fill it with mid 50% gray and then dodge/burn this layer (like an adjustment layer). There many other ways to go.
Often digital noise will be hiding in the shadows (only expensive gear has good shadow detail). When you lighten, noise is revealed. This is where grain/noise reduction methods are popular.
Does that help? Can a topic be expanded on in greater depth or with links to other info? http://members.ozemail.com.au/~binaryfx/PSTV_links.html