(EDIT: I wrote the title when I thought the "problem" was related to GET form submissions - however, it seems to be far more general.)
I've just noticed that Opera does not display querystring parameters in the browsers address bar?! Do others see this? Is this a new thing? (Chrome and Firefox show the querystring like normal.)
The querystring is correctly processed - it is there. However, the URL in the address bar does not show the querystring until you move focus to it - at which point you then see the full URL. However, move focus away again and the URL parameters vanish.
I thought at first this was a problem with my HTML form (submitted via GET), but it seems to be any querystring params on any page!?
It's possible that you have a site that simply varies the querystring from page to page - in Opera it will look as if the URL is not changing.
I'm using Opera 17 (I seem to have been automagically updated from version 16 when I wasn't looking ?!)
I've just found this "Security @ Opera" blog post from a couple of months ago (25 July 2013) about "The Opera address bar" and this mentions the removal of the querystring in the URL:
After looking at how URLs were used today, we also decided to remove the query part from the visible display rip, as we did not find that it would help users understand where they were and what they were looking at.
...followed by numerous comments saying what a bad idea it is!
In fact I have come across threads from a few years ago on this same subject of Opera not showing the querystring! However, it has always been possible in the past to disable this "feature" in settings, to always show the full URL. (I guess this is what I must have done previously!?)
Where's the "jumping up and down screaming in rage" emoticon when you need it? Isn't this the same thing FF did a few dozen releases ago when it benevolently decided not to show the protocol in the address bar? I assume bookmarks still store the whole thing; it's purely a matter of visible display.
At this point the internet-using world can be divided into people who know what an address bar is and people who don't. Are browsers trying to destroy the difference? "The address bar shows exactly where you are, excluding how you got there-- because you don't need to know-- and the essential details of page construction-- because we don't want you to trouble your pretty little heads about that-- and, heck, let's leave off www too to make it all tidier, and as long as we're at it we'll omit those pesky extensions."
People who use short pretty user-friendly URLs can gloat, because they are unaffected.