YES! I had this problem.
1) Uninstall the Ubuntu Opera package
2) Download (and install) the Opera "Other/DEB Static" package directly from http://www.opera.com
HOW TO UNINSTALL OPERA
From command line:
sudo apt-get remove opera
From Synaptic: ( MintMenu->Administration->Synaptic Package Manager)
1) Scroll down to Opera
2) Click on "checkbox" (probably green) and choose "Mark for Removal"
3) Click "Apply" up top, in the tool bar
HOW TO INSTALL STATIC OPERA FROM OPERA.COM
0) IMPORTANT: Close/quit out of Synaptic first!!
1) Download package
2) Open a Nautilus window (i.e. your file management window)
3) Browse to the directory where the new Opera static .deb package is.
4) Double click on it; this should open the package installer tool.
5) Click "Install" in the upper right. Type in your password.
Doing this has completely fixed the horrible, unusable, dramatic slowdown that the Ubuntu package of Opera was causing.