I just tried out CWP last night and I'm very impressed. All that aside, I too got this error when creating a client account and then logging into the newly created client account.
The error Robert is referring to is the stats on the right hand side.
/usr/local/cwpsrv/htdocs/resources/client/include/java_include.php is where the error is but it's encoded.
I renamed the above file.
Copied (with winscp):
/usr/local/cwpsrv/htdocs/resources/admin/include/java_include.phpto
/usr/local/cwpsrv/htdocs/resources/client/include/java_include.phpWhich fixed the screen errors and displayed the stats.
This is not any official fix, it's just a way I found to get rid of the screen errors. Just thought I would post this for anyone else experiencing this problem.