I tried to checkout a project from our svn repository and recevied the following error:
While executing onClick in svncheckout.html,
...
ReferenceError: svn4dw is not defined

How should this be defined?

please tell me what version of dreamweaver and what operating system do you use?

same problem under MacOS 10.4.11, DW2004MX7.0.1 and the latest CVS4DW at begin of trial period:
<start content of error1>While executing onCLICK in cvscheckout.htm, the following JavaScript errors occured: AT line 343 of file .."Applications:Macromedia Dreamweaver MX 2004:Configuration:Commands:cvs4dw2:cvscommon.js": ReferenceError:cvs4dw is not defined<end content of error1>
clicking on ok brings up the same window again
<start content of error2>While executing onCLICK in cvscheckout.htm, the following JavaScript errors occured: AT line 343 of file .."Applications:Macromedia Dreamweaver MX 2004:Configuration:Commands:cvs4dw2:cvscommon.js": ReferenceError:cvs4dw is not defined<end content of error2>
and returns to the CVS Checkout page.
Any help is appreciated.

OS: Mac OS X 10.5.2 running on MacBook Pro
DW: MX 2004 7.0
SVN4DW: downloaded last week

I would need access (vnc) to you computer to gather more data about this issue. Please contact us at support@grafxsoftware.com.
Thank you.

For all who encounter this problem, we try to find out why is happening, seems a problem between PPC and Intel Mac versions.