for your system. It appears they use a utility to manage the BIOS functions directly through Windows.
TOSHIBA Hardware Setup is the Toshiba configuration management tool available through the Windows operating system. To access it:
Click Start, All Programs, Toshiba, Utilities, and then HWSetup, or click the TOSHIBA Hardware Setup icon in the Optimize tab of TOSHIBA Assist.
You may try checking the USB tab in HWSetup to enable or disable USB Legacy Emulation. Click apply to save the setting.
Try setting the HWSetup to defaults on the General tab. Make sure you record all of your current settings first before clicking the default button.
You could also try going into Windows Device Manager, clicking view, then select show hidden devices. Under the "Universal Serial Bus Controllers" heading, right-click on each entry and uninstall it. When all have been removed, reboot the computer and try your mouse again.
Here is a link to download the latest version of Toshiba's HWSetup although you may already be running it. Select the downloads tab and the HWSetp utility is on the 4th page of downloads. FYI -There are a ton of recently updated drivers and utilites for your system in the downloads section.
http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/modelContent.jsp?ct=SB&os=&category=&moid=2144779&rpn=PSLB8U&modelFilter=L305-S5894&selCategory=3&selFamily=1073768663&selModel=2144779%7CPSLB8U#I noticed a download called Toshiba Service Station for Windows Vista that states: "This software will allow you to check automatically for new software or driver upgrades from the Toshiba Internet server." This might be worthwhile to automate the driver updating process for you.
If all else fails, contact Toshiba support, especially if the system is still under warranty.
One last thought, do you have a bluetooth wireless mouse you could try?