Mixed case (upper and lower) string values get changed to lower case unexpectedly. (4278623)

Given the below conditions  in the View | Toad Options | Editor | Behavior | Syntax Highlighting:

    a. Identifier - Capitalization Effect: Lower
    b.  Reserved Word - Capitalization Effect: Upper
    c. Strings - Capitalization Effect: Unchanged

and given a mixed case string (e.g. 'HeLlO') if the following steps are taken, the string values are changed to all lower case permanently.

1. In the Editor type in with the single quotes.
      'HeLlO'

2. Now type in aa or bb or cc or words in consecutive lines above "enable."
      a
      a
      'HeLlO'

5. Put a single quote in front the first a to get 'a.
6. Do the same with the second a to get 'a.
7. Notice how 'HeLlO' are changed to lower case permanently.