Desativar cache de gravação
Como você mencionou que os logs estão armazenados em uma unidade flash compacta, convém tentar desabilitando o cache de gravação nessa unidade:
This option is usually the best choice for storage devices that you are likely to remove from the system frequently, such as USB flash drives, SD, MMC, Compact Flash, or similar memory cards, and other similar externally attached storage devices.
Open the Control Panel (icons view) in Windows 7 or Windows 8, and click on the Device Manager icon.
In Device Manger, double click on Disk drives to expand it, then double click on the listed storage device that you want to disable write caching for.
Click on the Polices tab. Under the upper Removal policy section, select (dot) Quick removal, or check the Turn off Windows write-cache buffer flushing on the device box, and click on OK.