I have a blog on Wordpress which shows me daily stats and countries who have visited my blog. So far according to my Wordpress stats, 11 different countries have accessed my blog, however Google Analytics is only showing 4 countries that have been on my blog today. So basically the country stats don't match up, plus the amounts per country are different. So for example, my Wordpress stats show that today there's been 49 views from United States and 18 views from United Kingdom. However, my Google Analytics stats show that there's more from UK and less from US (so it's the opposite of my Wordpress stats). Plus the actual countries themselves are completely different, with my Wordpress stats counting countries such as Malaysia, Serbia, Australia, NZ, Ireland, India, while Google Analytics is showing China, UK, US and Egypt?! These stats are supposed to be for the same blog, on the same day, and yet they're completely different. I tried to change the timeframe on Google Analytics to ensure it getting the stats for today, however it will go between showing these results and not showing anything at all, even though it just was just displaying results from today!
Re: Inaccurate Countries
You could even get different results on the same site from two tag based (like GA) analytics tools.
Just make sure you have GA installed on every page and in the proper place and compare the results over time.