I have a Blackberry 8310 and am using an Israeli provider, Orange for calls.
I have OS 4.2x and after changing the apm to "Internet" i can indeed access www. I cannot see the BBbrowser, but use the Google maps app to verify web access.
Now, on attempting to install the Opera 4 browser from my PC, i get the "no applications for your device" error message. This is bizarre as other folks on th forum have indeed managed to install.
On the Opera site, i do not see a "high memory" version mentioned here.