Both these questions are about Google Analytics and are very similar, so I grouped them together.
Q: We currently use Google Analytics, and tried to upgrade to the new ga.js tracking code but were getting inaccurate, unusually high bounce rates. We have reverted back to the urchin.js tracking code and our bounce rates have returned to normal. Have you experienced this problem, and how would it impact our testing if we were to use the old tracking code vs. the new code?
Q: We recently installed the new Google code and our numbers were off. We found that the new code has issues with visitation, time spent on site and bounce rate. We went back to the old code and all the numbers were back to normal. Is Google fixing this?
A: We have not experienced the specific issues you identified, but without knowing more details about your specific implementation, the problems you had are hard to diagnose. You may want to look at some of the following notes:
1.) When GA.JS was in beta and during the first few weeks of launch, in December, there were some minor issues with the data collection. From our experience, most of these have been resolved.
2.) The original code for ga.js launched in December had issues with Blogger and ASP sites served by IIS. There is now an updated version.
3.) When you are migrating from urchin.js to ga.js you must ensure that you do not have both urchin.js and ga.js code on the same page. urchin.js and ga.js do not play well together and as a result can cause discrepancies in your data. Google has a migration guide available that could be helpful for you. It's available on the Google Code site for Google Analytics. Keep in mind these guides are still in beta:
4.) There is a known issue with the Google Web Optimizer tags blocking out the eCommerce tracking data in GA. Google is working on a fix for this and there is a workaround available in the interim.
Not updating your code to ga.js should not affect your testing at this time, but it will prevent you from getting access to new features that come out.
Also, sooner or later the urchin.js code will stop being supported by Google, meaning that you will have to upgrade to keep using Google Analytics.