Some people have experienced difficulty with the cursor "jumping" around when dictating directly into WP8 and/or the text being jumbled.  If you are experiencing either of these problems, you might like to try making the following changes, discovered by the members of the NatPro/WP8 Users Group, to your set up.  (NOTE:  it is rarely necessary to make all of the changes.  Some of the listed changes will only take effect after rebooting your system.)
1)    make sure to download/install SR5 for WP8.
2)    try adding the /fl command line switch.
3)    reduce your system's screen resolution to 640x480.
4)    change the WP8 display area to 1/2 screen.
5)    try switching to standard windows mouse driver and/or standard vga display driver.
6)    reduce display to 256 colors.
7)    Rename the default template (usually WP8US.WPT) to wp8us.old, reboot, restart WP and let
the program re-create it.
8)     Make sure that the WP8 keyboard is selected and that the shipping key assignments have not been changed; re-creating the default template will usually address this kind of issue.
9)     Turn off all automated, as you go, types of features in WP8 (if this solves the problem, you can
turn them back on one at a time to isolate the cause)
10)  try the SP1 for NaturalWord released on 2/14/00 - link for download on my page10.html
11)  No matter what you do, Nat version 4 and 5 will appear to have a "jumping" cursor if you use any shipping vocabulary word that has a hyphen in it and your cursor is within a table or a hyphenation zone.  Nat uses a hyphen code for hyphen instead of a hyphen character.  The same is true for a dash (which is just two hyphens).  You can see this for yourself by looking in Reveal Codes {Alt+F3} after dictating a hyphenated word.