Sorry that trick didn't work for you. Did you try installing it as a separate install, and testing it again? One time I did upgrade and something didn't install properly, and that was the result. It was somewhere around version 9.20 though, and a clean Opera install fixed it.

Well, for what it is worth I suspect many of the new features are behind the RAM usage. Not only can you search your browse history, but one of the new features allows you to do a full content search on all previously accessed webpages that you exited or closed out of. I'm sure that one is at least partly to blame!

I'll stick with it and see if there is something that can be disabled to fix the RAM usage. On the bright side the extra settings are helpful and the CPU usage is actually lower... 9.27 would usually work out to be 1-3% CPU usage for me, but this one reads 0% more often than not even as I type this.

Major update:

Opera 9.51 is released. You can now disable "Remember Content on Viewed Pages", and memory usage returns to Opera 9.27 levels. :)

Right now with 9.51: ~15 tabs open, been surfing for ~3 hours. 65mb RAM and 101mb page file in use. Much, much better...