Based on positive reviews from others in this forum I purchased a Huawei E355 USB dongle, shipped from Hong Kong by kfcore.com

Arrived in London yesterday to use it for the first time. Picked up a prepaid 1 GB hotspot SIM for £10.49 from the 3 store on Kensington High St.

Placed SIM into dongle and configured WiFi. Able to connect to WiFi and obtain IP from dongle but no 3G connectivity. Tried two locations to see if it was a signal problem. When I point the browser to the dongle's home page I get "The SIM card has not been detected or is invalid".

Any brilliant ideas?

Robert