Serial driver problems with 5.2-current

hello all.

   i see the following problems in my dell notebook.
FreeBSD vagisha.sudheeraj.net 5.2-CURRENT FreeBSD 5.2-CURRENT #0: Thu Dec 25 13:08:23 EST 2003     root_at_vagisha.sudheeraj.net:/usr/obj/usr/src/sys/VAGISHA  i386

The serial driver for my 3ccfem556 card hangs the machine hard. 
i just added a simple makefile in src/sys/modules to make it a module. (else it won't boot at all )

# kldload sio


Dec 25 19:33:10 vagisha kernel: sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa
0
Dec 25 19:33:10 vagisha kernel: sio0: type 16550A
Dec 25 19:33:10 vagisha kernel: sio1 at port 0x2f8-0x2ff irq 3 on isa0
Dec 25 19:33:10 vagisha kernel: sio1: type 16550A
Dec 25 19:33:10 vagisha kernel: sio4: <3Com Megahertz 3CCFEM556B> at port 0x120-
0x127 irq 11 function 1 config 39 on pccard1
Dec 25 19:33:10 vagisha kernel: sio4: type 16550A with a buggy IIR_TXRDY impleme
ntation
Dec 25 19:33:10 vagisha kernel: sio4: unable to activate interrupt in fast mode
- using normal mode

--- and i have to use the power button to reboot.

If i compile a custom kernel with serial driver disabled, it works fine.

Can someone please help ?

dheeraj