I see this problem sometimes too. Everything can be working fine for awhile, then it's like the Finder stops caring to see if a folder contains new content so it will no longer see new files created by Windows in that folder. And if I delete files from the folder using the Finder, they don't disappear from the Folder window, instead the file names are still there and the date fields appear as ----. This happens on a folder basis. Other folders on the same Windows disk can be still working fine.
