Tools menu doesn't work properly, clicking also works weirdly

Hi there, very new to inkscape but there seems to be a problem with clicking, as odd as that sounds.

Using inkscape 0.48.4, downloaded using the installer, on Windows 8.

Let's say I draw a rectangle. The tools menu on the left does not allow me to select the selector tool so I can select that rectangle (or any of the other tools on the menu). It's like it doesn't recognise the click. Sometimes if I move my cursor over my windows taskbar, or minimise the inkscape window and then open it again, it then allows me to select it, but not always.

When I do use the selector tool, it only works as a rubberband, I can't click objects to select them. And subsequent clicks don't bring up the rotate arrows.

If I double click the selector, it comes up with the inkscape preferences, and here it's even stranger. In this menu, sometimes but not always clicking on an option works the first time, but then subsequent clicks don't select things. For instance if I click on a tickbox it doesn't tick/untick. I have to click on it and then press enter to make it tick/untick. Again, if I move my cursor out of the window it works again, but only once. This is also true in the fill&stroke menu, and I presume in all the others too.

I've only just downloaded inkscape (and reinstalled it a bunch of times to see if that helped), so I don't see how I could have messed up the settings. I also know it's not something to do with my touchpad because the same thing happens with my USB mouse, and all my other programs seem to work fine.

It's almost like the default settings for inkscape make clicking not work the way they're supposed to.

I'd be really grateful for any help.