It does sound like it might be a driver issue. Which model you have is important as Toshiba lists a different Touchpad Driver for the S1980 model of the E205. If you've already tried the 1904 and it doesn't solve the problem, goto Toshiba.com TechSupport and download this driver:
http://www.csd.toshiba.com/cgi-bin/...1980&selCategory=2756709&selFamily=1073768663 . Also select the right Bit type for your OS (Control Panel | System).
If its not a driver issue, it could also be a software issue. You find the touchpad under either the mouse and/or HID (Human Interface Device) in Device Manager.
You can adjust the settings through Control Panel. If there isn't a separate touchpad tab, it'll be under Mouse Properties. Its also where the check box for "Disable Touchpad When An External Mouse Is Plugged In" will be found.
Depending on your notebook's features, you may also be able to adjust a myriads of behaviors like sensitivity, double-click (tap) speed, sleep in corners, etc. will be found.
You can turn the touchpad "off" in either the software or Device Manager, but to do that there, "Disable" it Don't try to "Uninstall" it. If you uninstall it, it'll reinstall itself because it tells the machine its a system driver.You have to unlock it from the system folders to get rid of it through the uninstall routine, and its not worth the risk of messing up your system. It should be harmless sitting there disabled.
Let us know if either drivers and/or software took care of the problem, or changed it in some way (hopefully better).