I see similar errors very often. I use Google Chrome on OS X.

I also have a mobile broadband dongle (UK - T Mobile) which does weird and unpleasant things to the connection. (All images are proxied with poor quality versions, javascript is inserted into the page asking for key combos to improve image quality; all alt tags are re-worded, etc.)

I blame any sub-optimality on the shitty broadband from T Mobile and the weird proxies; then on overload from HN, then on errors I've made.