Last minute decision to do club 5k tonight. 18.40 or thereabouts so 10k pace. Felt fine for 2 miles and then legs started grizzling and reminding me they were quite tired. Still, good to do a short tempo run and blow the cobwebs away!
MsE: ignoring one rogue entry on Po10 (which suggests that a road relay leg is my best performance, but they have the distance wrong), my marathon is my 6th best performance. I think that as Radcliffe's record is so great compared to other runners, it is harder for women to equal other WAVAs. My 10k, HM and 5k pbs are all better WAVAs than my marathon pb but I would still say I'm a marathon specialist on the basis I convert up better than most.
If your splits are even up until the 3M point then it's weird and hard to know what is causing it (possibly eating too close to the start time, but what would be odd it that always causes a problem at exactly 3M each time). If your first mile is your fastest by far and your third mile is your slowest (assuming a pretty flat course), your answer is right there: starting too fast.