Looks like we can't reproduce the issue or there's a problem in the test case provided.
I have downloaded gxt-3.0.0-dp5.zip and unzipped it.
My project name is SenchaExperiments.
I have followed the instructions in the setup.txt file, and in following step 2b, added the following as the first .css reference in SenchaExperiments.html:
<link rel="stylesheet" type="text/css" href="SenchaExperiments/css/reset.css" />
However, while my bits of code to learn GXT seem to work, I keep getting an error message in the console:
[WARN] No file found for: /SenchaExperiments/css/reset.css
Where is the css/reset.css file? I didn't see any file with the name "reset.css" and so assumed this was some sort of built in thing that GXT would interpret correctly.
Was this missing from the DP5 download?