the following related information was copied/pasted from http://secunia.com/advisories/42653

Description
Multiple [moderately critical] vulnerabilities have been reported in Opera [10 and earlier], where some have an unknown impact and others can be exploited by malicious people to disclose potentially sensitive information and manipulate certain data.

1) An error in the handling of some web page content may result in that content being displayed on top of dialog boxes and can be exploited to e.g. tricking a user to trust a malicious download.

2) An error when handling Wireless Application Protocol (WAP) sessions due to form fields not being cleared when a new session is started can be exploited to disclose form data to other web sites.

3) An unspecified error exists. No further information is currently available.

4) Some unspecified errors exist. No further information is currently available.

The vulnerabilities are reported in versions prior to 11.00.

Solution
Upgrade to version 11.00.

SurfRight's Hitman Pro build 118 released.

Changelog here:
http://www.surfright.nl/en/hitmanpro/whatsnew

Existing users can update internally via the program. A free 30 day trial of the full program can be downloaded from:
http://www.surfright.nl/en/hitmanpro/
(After 30 days, it reverts to a scanner only).

Hitman Pro is a cloud-based multi-engine "2nd opinion" anti-malware scanner (+remover, if purchased). It is not a replacement for your real-time anti-virus or anti-malware, and since it does not run in real-time, should not conflict with them.

I have used the free version for over one year with no problems whatsoever. My one year review of it is here:
http://en.community.dell.com/support-forums/virus-spyware/f/3522/p/19350173/19764062.aspx#19764062

Opera 11 is now fully compatible with WOT (Web of Trust) http://www.mywot.com/en/blog/311-wot-launched-for-opera

Edit:  Opera 11 classifies WOT as an "extension" (and can be disabled or removed via:  tools / extensions /manage extensions )

I like the new version of Opera but i don't like the new address bar which shows only the main domain name and a part of the whole address. Do you know how to have address bar like previous versions?