0.7.5 to 1.4.9 firmware upgrade??

[Bruno Lopes F. Cabral]

Hi there

I have several USR2445 pccards, which are based on prism 
chipset with the following firmware info:

wlan0: NIC: id=0x8002 v1.0.0                                                    
wlan0: PRI: id=0x15 v0.3.0                                                      
wlan0: STA: id=0x1f v0.7.5

I'm using these cards with openap linux (on a USR2450
AP), hostap driver version 2002-05-19, kernel 2.4.17

hostap_cs: hostap_cs.c 0.0.0 2002-05-19 (SSH Communications Security Corp, Joun)
hostap_cs: (c) SSH Communications Security Corp <jkm at ssh.com>                   
hostap_cs: index 0x01: Vcc 5.0, irq 3, io 0x0100-0x013f                         
hostap_cs: Registered netdevice wlan0                                           

I'd like to know if it is possible/recommended to upgrade 
them to a newer firmware (i.e. 1.4.9) or it would be 
better to stick with the one it has now. 

my goal is to use the firmware wep encription of 1.4.9 
because the  driver's wep make the unit run about 25% 
slower (this "beast" has a 486SX/33 running the system),
but only if it is safe to do so

thanks in advance for any hints/tips on this topic

Cheers, 
!3runo
from Brazil