Hey, Im having the same issue as http://www.jthink.net/jaikozforum/posts/list/1621.page but i use Windows 7. Please help 
Cant save most files in 3.8.1 w7
i am also having the following error when moving between directories:
“you do not have permission to write to the write folder you specified”
it seems that the second issue was reslved by recreating the folder and the first issue was resolved by clearing my perferences files and reinstalling (possibly a new .exe released?)