I have encountered this problem before and did not have a solution for it, but now I have a second customer that uses Dreamweaver MX experiencing this. Previously the customer was able to see both the local and remote views of the Site Files (F8). Now the customer can only see one view at a time and clicking on the Split Window button (in Site Files) results in the Site Files window disappearing entirely. It takes a shutdown and restart of DW to even view the site files again and the problem persists. With two people having the same problem, I would think there might be information on this somewhere on the web, but couldn't find any through Google, nor by searching here. Any ideas? My split window button works perfectly, so I have little advice to give them. Thank you!