Stay within a certain Context or Processing Mode?

[MLM]

I've been implementing GTD at work and while I can't use my Palm I do find the system to be working quite well. My question is related to Next Actions. When I complete a Next Action in a particular Context, should the item go back to the InBox to determine the next NA? I have folders set up for various Contexts since most of my InBox is physical paperwork. I wondered if I could just put the item in the appropriate NA folder, especially if I know what Context the NA is in. Also, if after processing the NA you discover the next step will complete the project and will take under 2 minutes, can you just go ahead and complete it?

How important is it to stay within a certain Context or processing mode - processing InBox vs. processing Next Actions?

Thanks!