MFP won't log my exercise! HALP!

I work in a high stress job that doesn't allow for much dedicated exercise time. As such, I'm limited during the day to running around my office in a small circle. Sometimes I look like a jerk to my co-workers, flaunting my healthy state to them as I circle, but I can't fix what they think, right? Anyway, I decided to get my exercise in small bursts and log it in MFP as I do so. Here's my problem: if I run for six seconds, I put in that I'm sprinting or whatever for .1 minutes, and MFP credits me 1 calorie. Well first, I KNOW that six seconds is WAY more than one calorie, at least two calories so it's underestimating by 50% (and everyone on the boards says to only eat back like 50% of my exercise calories, which seems mean to me since I'm already not getting 50% credit for my exercise). But worse yet, when I go to save my .1 minute of exrecise, MFP doesn't even save that entry!!! How am I supposed to get past this limitation? I tried lying to MFP and logging it as .2 minutes, but MFP STILLL wouldn't take my entry. Maybe it knows I'm lying?