Very odd.
Both ITA matrix and AA.com when you search LON-BUD show the MA LGW-BUD Z fare as business class with a nice price of 160USD+tax. Does it actually book into business? rules state its economy, but the other 2 tell differently...

So they STILL havent sorted this out then? I emailed them about this when I was looking at LHR-BUD-ARN for £330 and got this reply:

"Dear Mr. Koksy,

Thank you for your message to American Airlines about business class on Malev.

You are correct. While Z class is business class on American Airlines, the designation of "Z" on Malev iis for economy.

If you select Business Without Restrictions you will receive a Business class fare, however, it is not the lowest fare they offer. In order to book the lowest Business class fare you will need to contact American Airlines Reservations or Malev Reservations by phone. Ask the phone agent about booking a fare with an "I" class. This fare will be £962.30.

We have reported this issue to the appropriate department and to the programmers.

Our AA.com Web Services will best handle your questions and concerns regarding this issue. Please call for immediate assistance.

United Kingdom: 7:00 a.m. - 7:00 p.m. GMT Mon-Fri 0207-365-0777
8:30 a.m. - 5:00 p.m. GMT Saturday-Sunday

American Airlines looks forward to hearing from you soon.

We appreciate your patience while we continue to technically fine-tune American Airlines website, AA.com."

Ah, that's what I thought.

I thought one of the pre-conditions for joining an alliance was booking class alignment. At least IIRC it is on Star alliance. OW must be different then

Very strange.

In my case, for upcoming MA flights, I noticed a similar discrepency between the business class itinerary I purchased on AA.com and the e-ticket receipt they sent (which noted economy). As AA.com still shows my seats in Business, I wrote to Web Services to inquire. They responded very clearly:
Until reading this thread, I hadn't given this any further thought; now though, I'm no longer sure at all where I'll be sitting on my way to BUD.

What's certain, however, is that this sort of ambiguity is all too common.

Naming of classes is also confusing. Most US airlines refer to the front cabin on USA flights as First whereas in Europe on a pan-Europe flight it is Business.

I used to get irate on reading books by the likes of Cussler and Clancy where the "heroes" boarded a plane in Europe (e.g. UK > Germany) turned north and flew First Class. Eventually the penny dropped that their audience wouldn't understand if they talked about Business!

This probably fits best in either the Oneworld or AA board rather than BA - I've moved it over the OW board.

Actually most of the planet has business, not first in a 2 class AC. Only the US and a few others call business class "First". But the moment the flight goes to YYZ or SJU it become business again.

Clancy et al. might have a point because there used to be first class on many airlines in Europe in the past. Yep, tiny planes in a three class layout.

If the domestic US First existed in European flights, it would be called Premium Economy.

The concept of "premium" is quite the different in Europe and US.

Just an update: when I checked-in the other day for my flight to BUD, it turns out after all that my ticket was only for economy class travel, despite earlier assurances from AA that I was reserved in business, after having purchased a fare labeled 'business' from AA.com.

I wrote in for a refund of the return portion of the ticket, as it wasn't what I had paid for, and was told the following:

While there may be good technological reasons why they can't manage to label appropriately the fares they sell, it's unfortunate that they are not more up front about the limits of their website: if I knew this (admitedly discounted) fare was only for economy, I would have bought an even less expensive ticket with another airline.

Their fauly, my loss. Hardly acceptable, even if it's unintentional.