Viewing angles

My LCD that is supposed to be 80 degrees each way seems to be failing on that from certain viewpoints. It's fine horizontal and fine viewed from above but even a slight shift of my eye level below centre screen causes it to darken from the top. In portrait mode it's even more noticeable and I have to have it tilted away from me on the right hand side and sit left of centre to get an even picture. It isn't so bad it's unusable but I'm sure there's better models out there. Have I bought a lemon here or is that how it is with most LCDs? I went for a Philips model as, though Eizo and Samsung are generally considered better models, they don't pivot. The Philips seemed the best specs-wise as far as pivoting LCDs are concerned. Maybe the NEC Multisync would have been the better option?

Jay