Installation info: WordPress Version: 2.01
Got it working, but took some shinnangans (never know how to spell that word). This is the code I eventually used:
<?php previous_post_link($format='« %link', $link='%title', $in_same_cat = false, $excluded_categories = '2'); ?>
This is a link taken from my single.php for a category 4 post that states "show the link, title, **NOT** the same Cat and exclude category 2". The key was in making the in_same_cat parameter false and then excluding the categories I didn't want to show. From what I understand it, I have to include 'and' between any further categories I want to exclude in the future.
I still think it's highly annoying that the Next_link_post function takes General as the parent category when all of my categories ARE parents. The more logical approach for future development would be to have a 'category' parameter which would work in opposite to the current exclude function. This is how many other functions like get_post work. Then I could state, "show the next link for $category='2'". The $in_same_cat parameter is confusing and where a post is assigned to more than one category, can cause problems (at least for me anyway.)
Sorry to rant on but I think this is important. I still think the Codex pages should be updated as a matter of priority. Whereas the depreciated functions may work for others, in my case I couldn't manage (note: I've also tried the above technique with the old depreciated tags using six parameters, in_same_cat='no' excluded cat='2' but in that scenario, only the arrows appear).
Out and out, thanks again tsguitar for your help on this. I appreciate it and it makes me glad to be part of an open source community when problems can be solved efficiently in this way.
All the Best,