Instant preview & auto loading of AMS package

[aparsloe]

In a new document, place a math inset  inside another inset, say a 
(yellow) note (although I discovered this with a math inset inside a 
custom inset) and insert a formula that needs a symbol from another 
package, say amssymb. In the attachments I've entered "1+1 \thickapprox 
2". LyX displays the formula correctly (cursor-inside.png) but when the 
cursor is placed outside the note (cursor-outside.png) instant preview 
doesn't display \thickapprox and you get what looks like "1+12". 
Changing the math option for amssymb from "Load Automatically" to "Load 
Always" corrects the display, but if "Load Automatically" means what it 
says, the formula should really display correctly with that option.

Andrew