diff -ua linux-2.6.19.2.orig/drivers/net/avm_cpmac/cpphy_entry.c linux-2.6.19.2/drivers/net/avm_cpmac/cpphy_entry.c
--- linux-2.6.19.2/drivers/net/avm_cpmac/cpphy_entry.c	2010-07-21 14:57:47.000000000 +0200
+++ linux-2.6.19.2/drivers/net/avm_cpmac/cpphy_entry.c	2011-05-02 16:02:37.532790545 +0200
@@ -86,6 +86,8 @@
     /* Print driver version */
     DEB_ERR("Version: %s\n", AVM_CPMAC_VERSION);
 
+    printk(KERN_INFO "cpmac: compiled with sizeof(struct sk_buff) = %d\n", sizeof(struct sk_buff));
+
     /* Initialize administrative array */
     for(instance = 0; instance < CPMAC_MAX_PHY; instance++) {
         cpmac_global.cpphy[instance].is_used = 0;