Index: drsdaq/History.txt
===================================================================
--- drsdaq/History.txt	(revision 27)
+++ drsdaq/History.txt	(revision 28)
@@ -11,2 +11,3 @@
 1/4/2009    Changes many 'char *' to 'const char *' to honour compiler warning
             on ihp-pc26 (newer version of g++ than on eth-vme02)
+2/4/2009    Intoduced check for magic number in RawDataCTX.cc
Index: drsdaq/RawDataCTX.cc
===================================================================
--- drsdaq/RawDataCTX.cc	(revision 27)
+++ drsdaq/RawDataCTX.cc	(revision 28)
@@ -39,4 +39,10 @@
   if (fread(RHeader, sizeof(RunHeader), 1, Rawfile) != 1) {
     if(!Silent) printf("Error: Could not read run header\n");
+    fclose(Rawfile);
+    return CTX_RHEADER;  
+  }
+  // Check magic number of run header
+  if (RHeader->MagicNum!=MAGICNUM_FILE_OPEN && RHeader->MagicNum!=MAGICNUM_FILE_CLOSED) {
+    if(!Silent) printf("Error: Magic number of run header incorrect\n");
     fclose(Rawfile);
     return CTX_RHEADER;