Within a few seconds there was a new order...
Remember that you see MtGox through an anti-DDoS proxy run by Prolexic. If your behavior of accessing MtGox resembled in any way a DDoS then your access to MtGox is being throttled.
Prolexic's detection algorithms are secret and neither your nor MtGox can obtain any detailed information about them.
If you have an access to different IP space try accessing MtGox from a different source IP. The throttling that Prolexic uses takes into account the behavior of whole subnets, not just singular IP addresses.