The only thing I could find in the way of a manual was a generic Tasco instruction sheet
for their scopes, it may be of some help.
Check to see if your eyeball adjustment is in or out too far, I just backed my BSA Catseye out until the image got blurry at 100 yards, then tried to focus using parallax adjustment and it had to be set on infinity
to bring the picture back into focus. This sounds like the opposite of the problem your having, but the eyeball adjustment on my scope was already in as far as it will go.