Manufacturer: 1394 OHCI Compliant Host Controller Driver version 6.1.7601.17514 (and it's up to date)
Driver Provider: Microsoft
I've read a lot online about issues with the default firewire devices with this particular laptop model, and laptops in general.  So I think getting a TI chipset should do the trick. 

do the roll back dirver thing i showed you on the video ....it's not a question of up to date , but what kind of driver ....

The problem with laptops and FireWire is that the cardbus slot also has a chipset that interfaces between the card you're going to use and the computer hardware. Dell often use a Ricoh chipset as the cardbus controller and it is known to be very flaky in connection with FireWire. So even using a TI chipset FireWire card in some cases is of no help if the cardbus chipset itself is dodgy.

Unfortunately you can't tell beforehand what the outcome will be. At least it's not a super expensive experiment. Hope it works out.

Lindy 51499 ExpressCard works perfectly with my E6520
 
Dell's tech service claims E6520 uses Foxconn firewire chipset. ...!

Well, I've been testing for a few days with the new firewire express card and everything is working well now.  The express card is a little annoying and sits right on top of the dvd drive, but not annoying enough to spend another $200-$300 on a new usb audio interface (not yet at least)

Floyd have yuou tried what i told you before that ?