Do you have any other IDE plugin's installed?
If you change the colour:
VA Options -> Advanced -> Correction -> underline mistyped symbols using
does the underlining in the code change to use this new colour?
If you place the caret into "testvar" on the problem line what, if anything, does VA show in its context and definition fields (at the top of the editor)?
If you move the caret into the "my_test" what does it show then?
One possibility, something in your stable include directories is confusing VA. Can you try this code instead:
struct UniqueNameStructUnderlineThingSquareBanana {
int testvarAboutBanana;
};
int looksLikeMain()
{
UniqueNameStructUnderlineThingSquareBanana my_test_banana;
my_test_banana.testvarAboutBanana = 10;
return EXIT_SUCCESS;
}
This should at least elimiate problems over "Test" and "testvar" being known symbols from somewhere.