[c-nsp] USB to serial converter

[Chris]

I bought a Prolific USB to serial controller
(http://tinyurl.com/35ocwv [ebay.com]) to get access to my Cisco 2950
switch through my laptop's USB port. I tried from OpenBSD 4.2 on
/dev/ttyU0 and /dev/cuaU0 using cu, tip and minicom with baud rate
9600 and 8,N,1 with no luck. I also tried from Vista with Hypter
Terminal on COM4 but it's not responding. The only thing I get from
OpenBSD with /dev/ttyU0 is a lot of garbage characters at the
beginning (nothing happens after the garbage) -

..5%(.!3..=.((((3'=./A-#-.(((('!=7A/5'.5((((;!!. .-.9/.('5.
..5%((W/5(3!''!.-#1(9!%%=#7.(.-''(-#-.-='-53'=./(3-'5.
..5%(/=.(;55#(-#.5..57(.!.!(-#-.-='-.=..=..9..9.9.O%!75%(3-

The device is detected on OpenBSD as Prolific Technology Inc.
USB-Serial Controller, rev 1.10/3.00.

Could anyone help me with a solution or recommend a new converter for
Cisco 2950 switch?

Any help would be really appreciated. Thanks.