Q: Putting Photos from computer onto iPad

When you specify the folders to sync you have to specify both the new folders and all old folders (those which have previously been synched). If you don't the old folders will be deleted. This is the way synched folders are removed from an iPad.

What type of computer, OS, and iTunes level are you using?

Another way. You can use a USB flash drive & the camera connection kit.

Plug the USB flash drive (works the same with an SD card) into your computer & create a new folder titled DCIM. Then put your movie/photo files into the folder. The files must have a filename with exactly 8 characters long (no spaces) plus the file extension (i.e., my-movie.mov; DSCN0164.jpg).

Now plug the flash drive into the iPad using the camera connection kit. Open the Photos app, the movie/photo files should appear & you can import. (You can not export using the camera connection kit.)

Using The iPad Camera Connection Kit

http://support.apple.com/kb/HT4101

 Cheers, Tom

If you wish to sync multiple folders to your iPad on Windows then these folders have to be contained in a single "container" folder as subfolders. You select the single container folder to sync and just add new folders to it.

See the information describing this here: http://support.apple.com/kb/ht4236