No way for FileStore to be closed

If I create a ThreadedSocketInitiator with a FileStoreFactory, start, stop and re-start it, I get the following in stderr:

File delete failed: ...\FIX.4.2-xxx.header
File delete failed: ...\FIX.4.2-xxx.body
File delete failed: ...\FIX.4.2-xxx.seqnums

This seems to be because ThreadedSocketInitiator gets a new FileStore from FileStoreFactory which then locks files (for example - initializeMessageIndex opens a FileOutputStream for the header file).

When I stop the initiator this FileStore is never closed - the FileStore doesn't actually have any kind of close or dispose method.

When I restart the initiator it gets a new FileStore which barfs with the above errors when it can't delete the files.

I'm happy to work up a patch for this but would appreciate some guidance as to what the commiters think should close the FileStore.