mozzie wrote:I am a little confused - i thought a smaller aperture was meant to increase sharpness?
But i do think the faster shutter speed would be a good thing to try out
Don't confuse sharpness with depth of field.

Seriously ... the two are related, but are not (quite) the same thing.
Depth of field is an optical property that can be mathematically calculated given certain properties of a given lens. As you increase the aperture (numeric value) you reduce the physical size of the aperture opening, and thus gain a greater area of depth of field available to your lens. DoF relates to the range of an area within an image that is rendered in sharp focus.
But as I said, this is an optical property that can be mathematically calculated, and there are formulae available for just this task.
The apparent sharpness of a lens is more of a physical property ascribed to any given lens, and it varies from one lens to the next, even from lenses of exactly the same type.
Firstly, as you move your lens through its range of aperture settings, you will be increasing the DoF that your lens provides, but at the same time, you will also progress through a range of sharpness levels. Typically, many lenses are at their sharpest when closed down a stop or two; I would expect your lens's performance to be at its optimal at around f/5.6 - f/11.
Sharpness relates though to the level of detail that a lens may be able to resolve. Consider, say, the fabric on a shirt - the texture of a weave, the fineness of the sewing, and so on. Or the details - pores, blemishes, etc - that may be apparent on the surface of somebody's skin. Different lenses resolve these factors differently, and the sharper the lens, the greater the level of these details that may be seen.
Does this help any?