Recently I noticed that my vs2010 was auto lower casing my html attributes. This does not go very well with the use of dojo since onclick != onClick and dojo.query([Attribute]) != dojo.query([attribute]).
Now I’ve fooled with the VS options before and went straight to Tools > Options > Text Editor > HTML > Formatting to set client attributes to as entered. Well these two options are disabled.
I’ve disabled all my extensions and addins as best as I know how and it is still unaffected. Searches are not returning anything helpful.
What is causing these drop downs to disable?

If you go to Tools|Options|Text Editor|HTML|Validation, your Target markup is probably set to XHTML or some markup where you have no choice. Set it to something like HTML5 (not XML) and those options will light up again.