pdfsam is failing on pdfs created with protime (sap)

i am trying to merge pdfs with "pdfsam" which is working great normally but when i am using pdfs from "protime" pdfsam is showing a java-exception. its selecting all other files and is ignoring the file which was causing the excpetion. I needed i could provide the affected pdf directly but dont want to add it to this bug.

14:48:34,767 INFO Starting PDF Split and Merge basic Ver. 1.1.4
14:48:35,590 INFO Loading configuration..
14:48:36,261 INFO Getting language...
14:48:36,921 INFO Setting look and feel...
14:48:37,236 INFO Setting logging level...
14:48:37,241 INFO Logging level set to DEBUG
14:48:38,487 INFO Split plugin loaded.
14:48:38,798 INFO Merge/Extract plugin loaded.
14:48:40,465 INFO PDF Split and Merge basic Ver. 1.1.4 started in 5s 648ms
14:48:45,257 DEBUG Checking if a new version is available.
14:48:45,899 INFO New version available.
14:48:55,797 INFO File selected: A969FF.pdf
14:48:55,846 INFO File selected: A9QMMC.pdf
14:48:55,878 INFO File selected: E3L2XU.pdf
14:48:55,905 INFO File selected: EMXVTG.pdf
14:48:55,925 INFO File selected: FLA3P7.pdf
14:48:55,958 INFO File selected: NHOG9C.pdf
14:48:56,003 INFO File selected: ProTime_Reporting_02_2013.pdf
14:48:56,214 ERROR Error:
java.lang.NoClassDefFoundError: org/bouncycastle/asn1/ASN1OctetString
 at com.lowagie.text.pdf.PdfEncryption.<init>(Unknown Source)
 at com.lowagie.text.pdf.PdfReader.readDecryptedDocObj(Unknown Source)
 at com.lowagie.text.pdf.PdfReader.readDocObjPartial(Unknown Source)
 at com.lowagie.text.pdf.PdfReader.readPdfPartial(Unknown Source)
 at com.lowagie.text.pdf.PdfReader.<init>(Unknown Source)
 at org.pdfsam.guiclient.commons.business.PdfLoader$AddThread.getPdfSelectionTableItem(PdfLoader.java:269)
 at org.pdfsam.guiclient.commons.business.PdfLoader$AddThread.run(PdfLoader.java:242)
 at org.pdfsam.guiclient.commons.business.PdfLoader$WorkQueue$SingleWorker.run(PdfLoader.java:481)
Caused by: java.lang.ClassNotFoundException: org.bouncycastle.asn1.ASN1OctetString
 at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
 at java.security.AccessController.doPrivileged(Native Method)
 at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
 at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
 ... 8 more
14:48:56,281 INFO File selected: ZMMUKW.pdf

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: pdfsam 1.1.4-1
ProcVersionSignature: Ubuntu 3.2.0-37.58-generic 3.2.35
Uname: Linux 3.2.0-37-generic x86_64
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: amd64
Date: Mon Feb 18 14:49:59 2013
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: pdfsam
UpgradeStatus: Upgraded to precise on 2013-01-15 (33 days ago)