Been running Chrome (now on version 0.4.154.22) on Windows XP (SP3) for past week and despite trying EVERYTHING I can find on numerous Chrome forums/help pages, I still can't get Chrome to open Java applets. Always get a prompt:
"Java (TM) Platform SE6 U10 (Beta) plug-in is not installed, click here to download plug-in".
Java SE6 U10 is already installed and working.

Any ideas anyone, or is this still a Chrome 'glitch'? - I don't see it in their known issues list!

Managed after much trial and error to fix this problem - as is often the case rather simple. Java updater downloads and installs the latest versions of Java as they become available but doesn't erase the old versions. When I went into add/remove programs and systematically uninstalled the older versions of Java, Chrome started working (Java 6 either update 5 or 7 seemed to be the culprit). Not sure if it's a Chrome, Java, or XP/registry problem - don't know enough about computers, but hey Chrome seems to be working.

I've had the same problem - and solved it by reviewing your answer.

First, you don't need to uninstall existing JREs.

I've got about four different versions of Java installed (both SDK and JRE). Using ProcMon.exe (http://technet.microsoft.com) did the trick.

chrome.exe accesses the registry key HKLM\Software\JavaSoft\Java Runtime Enivronment.

It reads HKLM\Software\JavaSoft\Java Runtime Enivronment\BrowserJavaVersion.

In my case this entry pointed to 1.6.0_07. I changed it to point to 1.6.0_10 (it's not the Beta release mentioned in Chrome's help message) and ...there we go.

No warranty about other applets/applications that might need a lower Java version. I just wanted to get Chrome up and running.