The drag and drop seems to be ok. Get a minor error about lack of directories on open (after renaming a non empty data) If I do it properly it's fine. (create data and then drag stuff on to it)
Crash on exit - Caused by viewing item in external application. eg. PCS2, Infranview
VPEdit will then crash on each attempted start until the external application has been closed. (maintemp not empty)
************** Exception Text **************
System.IO.IOException: The process cannot access the file 'C:\VPEdit\maintemp\1\data\maps' because it is being used by another process.
I hope these ones are minor

Crash exporting single file
************** Exception Text **************
System.IO.IOException: The filename, directory name, or volume label syntax is incorrect.
Crash on exporting directory
************** Exception Text **************
System.IO.DirectoryNotFoundException: Could not find a part of the path 'C:\FreeSpace2\TVWP\data\intelanims\JC.ani'.