Finally got around to switching off first letter capitalisation (capitalization) For word 2007 and visio 2003.
The options are in the AutoCorrect Menus if you know how to find them. Microsofts instructions for Visio are here:
Basically, Visio -> Tools -> AutoCorrect Options, DeSelect "Capitalize first letter of sentences"
For Word 2007 I had to make the mistake then select the smart tag to get to the Auto correct options. but then the options were very similar to Visio.