Just wondered if what I'm experiencing is normal.

I always try to keep my audio levels at a strong level without ever clipping whilst inside XPro. Maxing somewhere between 0 and +10 on the VU side with reference level set at -14. Even so I find I have to adjust my TV connected to Mojo up from it's normal volume position to comfortably monitor my audio. Not a hectic amount, but enough to cause a shock to my eardrums if I happen to flick over the channel to catch up on the Olympics.

More worrying than that is that every DVD that I burn using a QTREF + Wav mixdown is considerably quieter than any Pre-recorded DVDs. I've taken to using a 200% volume increase inside Squeeze 5 to compensate (this wasn't even possible within Squeeze 4.5).

Is this normal or should I be getting a decent level straight out of Xpro?

Broadcast audio is often severely compressed/limited, so that the preceived loudness is very high. If you are making your own mixes in AXP without using any compression or limiting, it will be impossible for you to match broadcast mixes in perceived loudness, since your tracks will have way more dynamics.

Prerecorded DVDs come in many different flavors, but more often that not, their content has been processed to reduce dynamic range, and optimised for home viewing.

Avid AXP and MC/Symph have rather limited mixing options, unfortunately. However, in the AudioSuite plugins, compressor and limiter are available. You might want to mox down your audio, and apply a compressor or a limiter to your mix to reduce dynamics.