Just for your info...

Exact is off
ansi is off

but, with exact on and ansi on and I enter from the command window

? field = var && return = .t.
? var = field && return = .t.

There seems to be some anomally with the sql for some reason with the field line_id only. I have no problems with comparison order on ANY other comparisons. I give. Chalk it up to gremlins.