Is 10.51 only broken on XP?

Is 10.51 only broken on XP?

Opera 10.51 is so slow, I've started to use IE8!

Yes, it really is that bad.

After it automatically updating without asking, 10.51 has been unusable for me.
The first time I used it, I opened a PDF in a new tab like I usually do... closed it and crash.
It wouldn't restart, so I closed the process and eventually got it back up.
That's strange I thought, Opera is usually pretty stable, it must be Adobe. (I got round this by telling opera not to open PDF's in the browser)

Since then, I've been constantly wrestling with basic browsing, the main two problems seem to be:

1) Never-ending loading: Nothing appears on the page and the loading bar never disappears.
Oddly, sometimes if I click the stop button, the page then instantly comes up fully loaded.

2) Switching tabs doesn't work: the focus switches to new tab(it highlights), but the page being displayed doesn't change (This can be very confusing).

These problems happen completely at random, it doesn't matter what site I'm on. If I load the pages in other browsers they work flawlessly.

Does anyone know what the devs changed that has messed it up so badly?
Is it some new feature that we 'really' need? If not, can they change it back please, I miss Opera.

http://my.opera.com/community/forums/search.dml