Thanks for those links. I'll probably have one more go at re-arranging it before I give up. My meter is OK. Here is the picture of the layout. Is the inductor too big? It is 10uH.
Definitely parasitic inductance judging by the relatively large inductor and the long leads soldered to the chip.
I've been lucky enough in the past to have built RF circuits upwards of 400MHz on breadboard/perfboard, but usually anything above a few hundred kHz can get wonky quite easily. Some circuit configurations may work perfectly for a while then suddenly stop working. With HF in the circuit, it's all about getting the layout right.
Short lead lengths and
star ground configurations (if you don't have a solid ground plane) can help when prototyping. Manhattan style is quick and useful for prototyping if you're using leaded components (although mostly used for RF circuits).