Reading C register of RTC

[David Lopez]

Hello,
I use ioport in Linux to access RTC and read the registers.
The code works OK with physical hardware, but when run in a Linux guest in a VB (all versions included 6.1) on Windows 7 host, it always read zeroes.
Since this register gets cleared each time is read, I wonder if may be there is some process of VB or even Windows reading it, and if there is something I can to make it work.
Any ideas are welcome.
Thank you.