Fedora – Console port problems on Fedora 15

I've looked under every search term on google I can think of and can't seem to find anything that works.

I just switched from Windows 7 to Fedora 15 on my PC. I need use of the console port to interact with Cisco switches and other devices. However, I cannot seem to get it to work.
I've tried putty, and it says :

Unable to open connection to:
Unable to open serial port

I've tried minicom as well. Both putty and minicom I set up to /dev/ttyS0. I did have it working, once, connected with cat /dev/ttyS0, and it outputted the info from the switch, but when it got to the point where the switch expected input, it looped the input request message dozens of times a second.

I thought it might be a driver issue, but I cannot find any info for getting drivers for serial ports. I'm thinking I probably need to know the adapter model # or something. The port is built into the motherboard though, so I don't know if it has one.

I also tried setserial /dev/ttyS0, but it gives the message:

/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4

Is there a command to get info about the serial port/adapter? Is there something that I am doing wrong that I am not seeing?