Hi AP,
In addition to the reply we sent you this morning, I'd like to help you with the Little Math problem you mentioned here in your post.
This actually an issue with Windows XP, and is not because of Little Reader and Little Math. To remedy this, simply reinstall LM (assuming you have already installed LR 2.0) -- if you don't have the latest version of LM yet, I recommend that you download the installer from your Account Management page and install that one.
If reinstalling doesn't help, please try uninstalling LM (do not check any of the boxes in the "delete additional data" screen) first, and then open the LM installer again.
I hope this helps! We're looking forward to your reply (to our message from this morning) so we can start fixing all the problems you are encountering.