It's obvious how many people are still having this problem. I've gotten up the 'support ladder', but still no real joy from anyone. The issues aren't just matching to 'clean' versions - if you're matching a song that ISN'T actually available from your store (I'm in New Zealand, but have plenty of Canadian CDs that I've matched from), you can end up with a truncated song or a match to a song from a different album (so, from a Compilation album, rather than the original).
The ONLY thing that is going to get Apple off of their proverbials and fix these issues is legal action.
In New Zealand, they are already (likely) offside of the Consumer Guarantees Act (a service of product must be 'fit for the purpose' it has been claimed to) and the Fair Trading Act (misleading advertising - the product does not do what it was advertised to do).
Short of fixing the problem, Apple should offer the service FREE to those affected by the problem until such time as they have fixed it. This is the only fair resolution.
Otherwise, people should be seeking damages for their song libraries being harmed, along with the time spent in dealing with the issues.
My guess is that in the US, some intrepid soul will decide that 'enough is enough' and begin class action legal proceedings. Make sure you get onboard when that happens.