I recently upgraded Titanium. Existing apps, which are set to use the 1.3.2 SDK launch in the emulator just fine. If I set them to use the 1.4.0 or create a new project (which defaults to 1.4.0), I get Java path errors:
[ERROR] Required jarsigner not found [ERROR] Required javac not found [ERROR] Required java not found [ERROR] One or more required files not found - please check your JAVA_HOME environment variable
My environment variables are all set and they look fine. I'm on Windows running Developer 1.2.1, which I downloaded just minutes ago.
I can set new projects to use the 1.3.2 SDK and they launch in the emulator.
Switching to a nightly build of SDK 1.4.1 fixed the issue. Looking at version.txt in my C:\Documents and Settings\All Users\Application Data\Titanium\mobilesdk\win32\1.4.0 directory, I see this:
version=1.4.0 timestamp=07/27/10 18:21 githash=d1e8c8
Perhaps something's amiss with that particular build.