Serial Sparkfun 2x16 display wrong characters

My just purchased Sparkfun serial enabled v2.5, 16x2 display is putting out wrong characters, Im using 9600 8n1 and have also tried faster and slower baud rates. Has anyone see this before? Examples of the wrong characters are below, first what is typed, then what is displayed. It is like the wrong ascii table is used.
a o
b ,
c N
d blank
e M
f &
g L

Hi Rob,

What was the SKU number for the exact display you purchased? Sparkfun have a number of different serial displays, so I can get on the same page, and work through it with you.

Woulod be worth sharing your code, in the shortest/cut back way you can which replicates the issue

Hi Sam / Graham,
the model number is a SKU: LCD-09067.
I was sending text from hyperterminal to the display. The characters displayed did not match my typing.
Baud 9600 8n1.

Thanks Rob. What device are you using to convert the signals from the PC to 5V TTL?

Also, do you have a common earth between the above device and the LCD-09067?