Data corrupted when sending large files at 115200 bauds

[jlder]

Testing an OpenLog with a Windows PC using an USB/Serial interface for large data transfer at 115200.
I run Advanced Serial Port Terminal and Realterm on Windows, with same results.
I send a 100KByte file.
If I set the USB/serial interface to 8 bits, no parity and 1 stop bit, I get garbage in the OpenLog.
If I use 8 bits, Space parity and 1 stop bit, I get perfectly good communication.
It is like the 8 bits are shifted and it requires a ninth bit at zero to get the correct value (I only send ASCII data).
Has anybody encountered the same problem?