The company directory is still not working in Android 2.2 at least on my EVO 4G. But the good news is that you dont need it to work. There is a better way. I kept thinking that Google was supposed to be the king of searching, so I could not accept the fact that you cannot atleast search by company name. After doing some digging I found out a way to find contacts by company name.
Press the "+" sign next to "Phone" on your home screen then select "Widgets" next select "Google Search" then select "People" and place the search bar on your home screen. Now you can search your contacts by name, company, number, etc. You can select the contact and see the full contact info for that individual and dial the number from there. You can also have the search pull up related email, texts, etc. when you search for the individuals name.
Press the "+" sign next to "Phone" on your home screen then select "Widgets" next select "Google Search" then select "People" and place the search bar on your home screen. Now you can search your contacts by name, company, number, etc. You can select the contact and see the full contact info for that individual and dial the number from there. You can also have the search pull up related email, texts, etc. when you search for the individuals name.