I had the same problem as others here. My mouse didn't jump to the top of the screen but it was clearly flaky. The mouse appears to work on computer restart/power recycle or if I unplug and plug in the lachesis. But the problem eventually manifests itself clearly showing symptoms of jumping.
Its as if the hardware interrupts that the mouse generated were deliberately given a delay of milliseconds. But enough to cause you to miss pointing exactly where you want to.
Anyway, I played with motherboard BIOS settings and then tried to update the firmware. Razor still does not have Windows 7 64bit support for firmware installation no matter what they say on the website. It simply does not work regardless of which OS compatibility mode you try (or the recommended one from Windows 7 which is XP SP2). Having read of some users having issues with updating the firmware on another machine and having problems when plugging in the mouse again on the Windows 7 x64 machine, I decided against doing this step. My firmware is still 1.91 even though there is a later version out.
So
drivers stand at 1.10. I also had the
drivers details report that it is version 1.00 regardless of what I do to them. Anyway, I had to do what some users here suggested. Go into device manager and uninstall anything that looked like it might be related to the Lachesis mice (including HID compliant devices indicating they were Lachesis related). I even uninstalled the PS/2 mice that my system thinks it had (although this re-installed itself on restart).
At the end of the day, the
driver properly installed itself. I am not sure where it got the
driver from although I did install Razorware initially. So it either found the Razorware
drivers for Lachesis and properly installed it this time or used some Microsoft certified drivers (Windows 7 comes with a lot of ready certified drivers which Microsoft tests/certifies).
Now my mouse is no longer playing up. It is clearly a
driver installation issue and Razor's device driver routine is making too many assumptions about how clean my machine is or is not doing checks to ensure all the registry keys, files, etc are properly registered.
I had a similar problem with Apple iTunes not too long ago in Windows Vista Ultimate (32bit) where it continually fails to recognise the Apple iPhone and I had to do a lot of things manually to get it to work. I could repeat the problem on another machine as well. Apple eventually fixed the problem in subsequent iTunes releases.
To the software developers creating Installshield/Wise software packages that install hardware device drivers - Vista and Windows 7 driver installation is not as straightforward as the books may lead you to believe. I think the real world has more than just cleanly built machines and you need to ensure your driver installation processes cleanup, check, install, check again and cleanup again where necessary to get the drivers to install.