Have you changed anything since your bike fit? (saddle, shoes, cleats, bars, etc) If not, then it's probably fine.

Is the pain that you're feeling similar to your IT band pain (location, severity, "type" of pain)?

The area that you're talking about (above the knee) is usually the first muscle that's going to burn/hurt when you're pushing yourself. If it aches while you're going uphill but then seems to be back to normal by the time you coast a bit and get down the other side, then it's more than likely just normal lactic acid burning. If that's the case, then follow your friend's advice and push through it if you can, because that type of pain gets better with improved fitness. (Actually, that pain remains the same, but as you get more trained, you'll just be going faster when you feel it- hence the quote, "It never gets any easier, you only get faster" )

If it's pain that's like your IT band injury- like something that gets worse as you ride whether you're really exerting yourself or just riding on flat ground- then it's a sign that you may have an actual injury, which is a sign that you should see a doc.