So, the let's try this idea yet: modified Ingo's "x86: activate
HARDIRQS_SW_RESEND" patch.
(Don't forget about make oldconfig before make.)
For testing only.

Cheers,
Jarek P.

PS: alas there was not even time for "compile checking"...

---

diff -Nurp 2.6.22.1-/arch/i386/Kconfig 2.6.22.1/arch/i386/Kconfig

--- 2.6.22.1-/arch/i386/Kconfig 2007-07-09 01:32:17.000000000 +0200
+++ 2.6.22.1/arch/i386/Kconfig  2007-08-07 13:13:03.000000000 +0200

@@ -1252,6 +1252,10 @@ config GENERIC_PENDING_IRQ
        depends on GENERIC_HARDIRQS && SMP
        default y

+config HARDIRQS_SW_RESEND
+       bool
+       default y
+
 config X86_SMP
        bool
        depends on SMP && !X86_VOYAGER

diff -Nurp 2.6.22.1-/arch/x86_64/Kconfig 2.6.22.1/arch/x86_64/Kconfig

--- 2.6.22.1-/arch/x86_64/Kconfig       2007-07-09 01:32:17.000000000 +0200
+++ 2.6.22.1/arch/x86_64/Kconfig        2007-08-07 13:13:03.000000000 +0200

@@ -690,6 +690,10 @@ config GENERIC_PENDING_IRQ
        depends on GENERIC_HARDIRQS && SMP
        default y

+config HARDIRQS_SW_RESEND
+       bool
+       default y
+
 menu "Power management options"

 source kernel/power/Kconfig

diff -Nurp 2.6.22.1-/kernel/irq/manage.c 2.6.22.1/kernel/irq/manage.c

--- 2.6.22.1-/kernel/irq/manage.c       2007-07-09 01:32:17.000000000 +0200
+++ 2.6.22.1/kernel/irq/manage.c        2007-08-07 13:13:03.000000000 +0200

@@ -169,6 +169,14 @@ void enable_irq(unsigned int irq)
                desc->depth--;
        }
        spin_unlock_irqrestore(&desc->lock, flags);
+#ifdef CONFIG_HARDIRQS_SW_RESEND
+       /*
+        * Do a bh disable/enable pair to trigger any pending
+        * irq resend logic:
+        */
+       local_bh_disable();
+       local_bh_enable();
+#endif
 }
 EXPORT_SYMBOL(enable_irq);

diff -Nurp 2.6.22.1-/kernel/irq/resend.c 2.6.22.1/kernel/irq/resend.c

--- 2.6.22.1-/kernel/irq/resend.c       2007-07-09 01:32:17.000000000 +0200
+++ 2.6.22.1/kernel/irq/resend.c        2007-08-07 13:57:54.000000000 +0200

@@ -62,16 +62,24 @@ void check_irq_resend(struct irq_desc *d
         */
        desc->chip->enable(irq);

+       /*
+        * Temporary hack to figure out more about the problem, which
+        * is causing the ancient network cards to die.
+        */
+
        if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
                desc->status = (status & ~IRQ_PENDING) | IRQ_REPLAY;

-               if (!desc->chip || !desc->chip->retrigger ||
-                                       !desc->chip->retrigger(irq)) {
+               if (desc->handle_irq == handle_edge_irq) {
+                       if (desc->chip->retrigger)
+                               desc->chip->retrigger(irq);
+                       return;
+               }
 #ifdef CONFIG_HARDIRQS_SW_RESEND
-                       /* Set it pending and activate the softirq: */
-                       set_bit(irq, irqs_resend);
-                       tasklet_schedule(&resend_tasklet);
+               WARN_ON_ONCE(1);
+               /* Set it pending and activate the softirq: */
+               set_bit(irq, irqs_resend);
+               tasklet_schedule(&resend_tasklet);
 #endif
-               }
        }
 }