Long binary data would be base64 encoded with newlines, which made the iCalendar files incorrect. (This still needs testing).

CHANGES.txt

@@ -1,3 +1,9 @@
+iCalendar trunk (unreleased)
+============================
+
+* Long binary data would be base64 encoded with newlines, which made the
+  iCalendar files incorrect. (This still needs testing).
+
 iCalendar 2.0.1 (2008-07-11)
 ============================
 

src/icalendar/prop.py

@@ -47,6 +47,7 @@ from types import IntType, StringType, UnicodeType, TupleType, ListType
 SequenceTypes = [TupleType, ListType]
 import re
 import time as _time
+import binascii
 
 # from this package
 from icalendar.caselessdict import CaselessDict
@@ -91,7 +92,7 @@ class vBinary:
         return "vBinary(%s)" % str.__repr__(self.obj)
 
     def ical(self):
-        return self.obj.encode('base-64')[:-1]
+        return binascii.b2a_base64(self.obj)[:-1]
 
     def from_ical(ical):
         "Parses the data format from ical text format"