The Notes 6.0.4 update can be downloaded here : http://www14.software.ibm.com/webapp/download/search.jsp?S_TACT=104AH+W42&S_CMP=&s=&status=Active&sr=1&cat=&k=ALL&dt=SOFTWARE+UPDATE&q=Notes+client+6.0.4&pf=&x=0&y=0&sb=n&sr=1&S_TACT=104AH+W42&S_CMP=&s=
This will allow the 6.0.x version of Lotus Notes to install and run under CrossOver Office. Please note: cxsetup will report an error for a NEW install of a full 6.0.4 client if you use the 6.5.1 option, use the "unsupported application" option to avoid the error, or just ignore the error. The upgrade patch should work, but I have not yet tested the patch installer.