i have a vgn-fe25gp and developed this problem yesterday after updating the VAIO Event Service to Ver.2.3.00.05310 from version 2.2.01.11040, which came preinstalled on the laptop.
i uninstalled this program from add/remove programs, and then reinstalled version 2.2.01.11040 from the system recovery dvd i had previosuly made, and this resolved the problem.
hope this helps others.:p