diff --git a/branches/ucs-3.0/ucs/base/univention-updater/debian/changelog b/branches/ucs-3.0/ucs/base/univention-updater/debian/changelog
index eb16755..0e71ba0 100644
--- a/branches/ucs-3.0/ucs/base/univention-updater/debian/changelog
+++ b/branches/ucs-3.0/ucs/base/univention-updater/debian/changelog
@@ -1,3 +1,9 @@
+univention-updater (7.0.156-1) unstable; urgency=low
+
+  * Skip using empty Packages (Bug #26983)
+
+ -- Philipp Hahn <hahn@univention.de>  Tue, 08 May 2012 16:48:06 +0200
+
 univention-updater (7.0.155-1) unstable; urgency=low
 
   * disable restart of UMC webserver in preup.sh (Bug #26298)
diff --git a/branches/ucs-3.0/ucs/base/univention-updater/modules/univention/updater/tools.py b/branches/ucs-3.0/ucs/base/univention-updater/modules/univention/updater/tools.py
index 4861182..ba7c267 100644
--- a/branches/ucs-3.0/ucs/base/univention-updater/modules/univention/updater/tools.py
+++ b/branches/ucs-3.0/ucs/base/univention-updater/modules/univention/updater/tools.py
@@ -60,6 +60,8 @@ import shutil
 RE_ALLOWED_DEBIAN_PKGNAMES = re.compile('^[a-z0-9][a-z0-9.+-]+$')
 RE_SPLIT_MULTI = re.compile('[ ,]+')
 
+MIN_GZIP = 100 # size of non-empty gzip file
+
 class UCS_Version( object ):
 	'''Version object consisting of major-, minor-number and patch-level'''
 	FORMAT = '%(major)d.%(minor)d'
@@ -346,7 +348,10 @@ class UCSHttpServer(object):
 		try:
 			res = UCSHttpServer.opener.open(req)
 			try:
-				return (res.code, res.read())
+				code = res.code
+				size = int(res.headers.get('content-length', 0))
+				content = res.read()
+				return (code, size, content)
 			finally:
 				res.close()
 		# direct   | proxy                                        | Error cause
@@ -957,8 +962,9 @@ class UniventionUpdater:
 								found_patchlevel = True
 								for ver.arch in archs: # architecture
 									try:
-										assert server.access(ver.path())
-										yield ver
+										code, size, content = server.access(ver.path())
+										if size > MIN_GZIP:
+											yield ver
 									except DownloadError, e:
 										ud.debug(ud.NETWORK, ud.ALL, "%s" % e)
 								del ver.arch
@@ -1091,8 +1097,9 @@ class UniventionUpdater:
 				if self.sources:
 					ver.arch = "source"
 					try:
-						assert server.access(ver.path("Sources.gz"))
-						result.append( ver.deb("deb-src") )
+						code, size, content = server.access(ver.path("Sources.gz"))
+						if size > MIN_GZIP:
+							result.append(ver.deb("deb-src"))
 					except DownloadError, e:
 						ud.debug(ud.NETWORK, ud.ALL, "%s" % e)
 
@@ -1139,8 +1146,9 @@ class UniventionUpdater:
 				if self.sources:
 					ver.arch = "source"
 					try:
-						assert server.access(ver.path("Sources.gz"))
-						result.append( ver.deb("deb-src") )
+						code, size, content = server.access(ver.path("Sources.gz"))
+						if size > MIN_GZIP:
+							result.append(ver.deb("deb-src"))
 					except DownloadError, e:
 						ud.debug(ud.NETWORK, ud.ALL, "%s" % e)
 
@@ -1194,8 +1202,9 @@ class UniventionUpdater:
 				if self.sources:
 					ver.arch = "source"
 					try:
-						assert server.access(ver.path("Sources.gz"))
-						result.append( ver.deb("deb-src") )
+						code, size, content = server.access(ver.path("Sources.gz"))
+						if size > MIN_GZIP:
+							result.append(ver.deb("deb-src"))
 					except DownloadError, e:
 						ud.debug(ud.NETWORK, ud.ALL, "%s" % e)
 
@@ -1371,8 +1380,9 @@ class UniventionUpdater:
 					if self.sources:
 						ver.arch = "source"
 						try:
-							assert server.access(ver.path("Sources.gz"))
-							result.append( ver.deb("deb-src") )
+							code, size, content = server.access(ver.path("Sources.gz"))
+							if size > MIN_GZIP:
+								result.append(ver.deb("deb-src"))
 						except DownloadError, e:
 							ud.debug(ud.NETWORK, ud.ALL, "%s" % e)
 
@@ -1563,7 +1573,7 @@ class UniventionUpdater:
 				path = struct.path(name)
 				ud.debug(ud.ADMIN, ud.ALL, "Accessing %s" % path)
 				try:
-					code, script = server.access(path, get=True)
+					code, size, script = server.access(path, get=True)
 					yield server, struct, phase, path, script
 				except DownloadError, e:
 					ud.debug(ud.NETWORK, ud.ALL, "%s" % e)