I'm also using an 8125 and the GTD Outlook Plugin on my office computer.
My tasks will show up in the approriate @Action lists if I filter by category. However, creating new tasks and editing existing tasks seems to break that relationship.
(I can't add a task, assign it to an @work category, and expect to see it show up in the @work action list when I sync).
I did explore (in terms of email) moving all messages once they been read on the PDA to a folder called pda, where I would then process them with the plugin once back in the office. This does keep my inbox clean.
But honestly, I'm just using the PDA as a notifier at this point. I know when an email comes in, I can read it, and when I sit back down at my desk, I don't have to re-read it before I process it.
Any better suggestions would be greatly appreciated.