Forwarding the ports seems to have fixed it for me. So thanks for that (not really sure why its worked fine for a few months without doing it but whatever!)!
Also having the same problem. Started as of the patch a few weeks back. Everything was fine before that.
Also have similar specs to you (64bit, BT Homehub3)
Had it three times tonight. All three times has been when stomped from stealth. Twice from a theif, once from an ele in a mesmer elite.
Different maps, playing different chars. Spread across about 3 hours.
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