I am curious if you just go to Google and enter the command remind me click search does it bring up the reminder options? Also I should have mentioned you will need to be logged into a Google Account on your browser.
So far I have tried the following while logged in to my Google Account. In Chrome desktop browser:
1. I've tried entering the URL that you use in your xml in the Chrome address bar, but replacing {1} with "walk the dog in 10 minutes" > I get regular search results but no reminder notification options.
2. I've tried entering the phrase "remind me to walk the dog in 10 minutes" into a Google search box. > Same result.
3. I've tried using Chrome's microphone/speech recognition with the same request. Same result.
4. I've tried simply typing "remind me" into Google search bar. > I get search results for the phrase "remind me" (mostly music videos)
5. I thought maybe my settings could be wrong in Chrome, so I went into the advanced settings to make sure notifications were on etc. and did the same tests again, with no difference in the results.
Since RoboB uses Internet Explorer, I also tried signing in to my Google Account in IE and executing your command with a few different payloads. No luck there either.
If the reminder notifications are working consistently for you, I'm wondering if Google Now on the desktop is a feature that only works in the U.S. currently, or if it has to do with something else that's different about our Google accounts, ... or ?