When i removed a two tile long land survey that was on my pclaim, i was left with a hole in the claim. Turning the show pclaims thing off and on again didn't fix it, but re-logging did. Either way, just thought i'd report it anyway.
EDIT: It happened again when i placed some dirt down, in the same shape. Now that i think of it, i think it was placing down dirt int he two tile survey, rather than removing it.
EDIT2: It did it AGAIN. Same thing as the first edit.