diff -ru portage.orig/pym/portage/busy.py portage/pym/portage/busy.py
--- portage.orig/pym/portage/busy.py	2010-07-26 16:19:32 +0200
+++ portage/pym/portage/busy.py	2010-07-26 16:20:31 +0200
@@ -32,12 +32,12 @@
 
 		self.cleanBusyFiles()
 	
-	def getDestFilename(self, srcfile):
+	def getDestFilename(self, destdir, srcfile):
 		"""calculate a destination filename based on the srcfile filename."""
 		my_fn = ".$busy-" + srcfile + "."
 		my_num = 0
 		
-		while os.access(my_fn + str(my_num), os.F_OK):
+		while os.access(os.path.join(destdir, my_fn + str(my_num)), os.F_OK):
 			my_num += 1
 
 		return my_fn + str(my_num)