Thanks for identifying and logging this one.
I did some testing of move operations, where I called xadisk rename operation with "src" and "dest":
1. within the same file-system
2. "src" being on a local file-system, "dest" being on a network shared file-system.
In both of these cases, the lastModified time was actually retained. I think the case where you observed the lastModified time not being retained is when the move is across different (incompatible) file-systems and these are the cases when the Java File's renameTo method fails. I had seen such examples of renameTo failing in past, so had introduced a workaround in XADisk. In such cases, XADisk does what unix "mv" does, i.e. creating the "dest" file, copying the content, and deleting "src" file, and hence the lastModified time is lost. I am planning to fix this by explicitly setting "dest" lastModified time using Java File's setter method.