red line through map- and files icons

can anyone tell me why there is a red line through the icons?

Indicates that those files and folders are cloaked in DW.

See Cloak files and folders in your Dreamweaver site

"Site cloaking enables you to exclude files and folders from operations such as Get or Put. You can also cloak all files of a particular type (JPEG, FLV, XML, and so on) from site operations. Dreamweaver remembers your settings for each site so that you don’t have to make selections each time you work on that site.

For example, if you’re working on a large site and you don’t want to upload your multimedia files each day, you can use site cloaking to cloak your multimedia folder. Dreamweaver will then exclude files in that folder from site operations you perform."