What are the risks associated with taking a semester off while doing a Master's degree? I am curious about this -  I'm currently undergoing a Masters degree and am almost finished.

I finished the coursework, however I still have the thesis project plus the thesis. And it's looking unlikely for the Spring semester.

My prof is a little bit agitated, but i'm just strapped for time. I'm working full-time and school is simply becoming second-fiddle to work. I come home from work, and if I'm lucky I can spend 20 minutes on school material. Weekends are tough also, as I travel to meet family.

However, I feel that taking a semester off only hurts my overall situation. Because even being registered for 1 hour of thesis credit is a sort-of motivation for me. I.E "OK i'm paying money so I better get my money's worth"

However I see the other argument which is "well if you knowyou can't graduate this semester then why not just do the work without paying.. then register  the following semester?"

But I am worried that there'll be some hidden snag associated with re-enrolling? 

Does anybody have advice/suggestions? Intuitively i'd rather pay-up and at least stay enrolled, but I caan sympathize with my prof's view.
I know several people who have deferred their degree's at all levels for one reason or another.  In all these cases, the student has spoken not just to their professor but to the relevant department admin person and it's been pretty straight forward to enrol and pick up from where they left off.  None of them have suffered from taking time out.

I think you need to ask yourself a couple of questions so you can figure out which is the best solution for you.  Here's a few that spring to mind....

Is taking a semester out really going to solve your time problem?  If you will have the same issue again the next semester you enrol in then taking time out is probably a little pointless.

If you take time out, do you think you will stay motivated enough to re-enrol again?  

If you stick with it this semester, what can you do to generate more time?  You mentioned you travel to see family at weekends - is this something you can stop doing for the semester or is visiting an absolute necessity?