serial port too fast for Core Duo?

[Dr. Michael J. Chudobiak]

I have an oscilloscope with a 19200 bps serial port on it. It works fine 
with my old Windows 2000 computer.

But it will not work with the on-board serial port on my shiny new HP 
DC7900 with Fedora 10! 19200 bps is too fast, and the data is always 
(slightly) corrupted, regardless of what sort of flow control is used.

Using a USB-to-RS232 dongle works, presumably because the dongle has a 
larger buffer than the normal 16 byte UART.

Can linux really not handle a 19200 serial port transmission, without 
resorting to obscure IRQ re-prioritization hacks?

- Mike