Index: LocalXWikiDataStorage.java
===================================================================
--- LocalXWikiDataStorage.java	(revision 36367)
+++ LocalXWikiDataStorage.java	(working copy)
@@ -52,9 +52,9 @@
 /**
  * This class implements a local data storage for XWiki elements that uses the Eclipse resource component. The local
  * storage is rooted at an IFolder passed to the constructor. The structure of the local storage is the following:
- *
+ *
  * <pre>
- * Root
+ * Root
  * + index
  *   + Space1 (directory having its name equals to the space key)
  *     + Page1 (directory having its name equals to the page id)
@@ -78,7 +78,7 @@
  *   |- Class1.xec (the actual class information)
  *   |- ...
  * </pre>
- *
+ *
  * All xe* files contains an XML serialization of the corresponding XWiki Eclipse elements.
  */
 public class LocalXWikiDataStorage implements IDataStorage
@@ -282,12 +282,13 @@
                         : new ArrayList());
                     pageSummary.setUrl(page.getUrl());
                     CoreUtils.writeDataToXML(baseFolder.getFolder(INDEX_DIRECTORY).getFolder(page.getSpace())
-                        .getFolder(page.getId()).getFile(getFileNameForPageSummary(pageSummary.getId())), //$NON-NLS-1$
+                        .getFolder(getFilenameFilesystemFriendly(page.getId()))
+                        .getFile(getFileNameForPageSummary(getFilenameFilesystemFriendly(pageSummary.getId()))), //$NON-NLS-1$
                         pageSummary.toRawMap());

                     /* Write the page */
                     CoreUtils.writeDataToXML(baseFolder.getFolder(PAGES_DIRECTORY).getFile(
-                        getFileNameForPage(page.getId())), page //$NON-NLS-1$
+                        getFileNameForPage(getFilenameFilesystemFriendly(page.getId()))), page //$NON-NLS-1$
                         .toRawMap());
                 }
             }, null);
@@ -481,6 +482,10 @@
         return objectFile.exists();
     }

+    private String getFilenameFilesystemFriendly(String url) {
+        return url.replace("?", "_");
+    }
+
     private String getFileNameForPageSummary(String pageId)
     {
         return String.format("%s.%s", pageId, PAGE_SUMMARY_FILE_EXTENSION); //$NON-NLS-1$