Hi @v2abcd - I suspect you have a Sentelic toucchpad, rather than a Synaptics. Do you disable the touchpad when using the mouse?
What version touchpad driver is currently installed?
What version WiFi driver is installed?
What version video driver is installed?
Aside from the mouse, are there other peripheral devices attached to your laptop?
Here is what I've done to eliminate keyboard lag and missing keystrokes:
http://rog.asus.com/forum/showthread...ll=1#post44735I'm unsure if you have the Atheros Wireless Network Adapter as discussed in Step 3. If you don't you can still run the DPC Latency Checker to eliminate latency on your system. This is a big part of eliminating keyboard lag/missing keystrokes.
If the above fail to resolve your missing keystrokes issue, it is likely a hardware keyboard problem and I recommend exchanging your laptop for a new unit.
Alternatively,
http://rog.asus.com/forum/showthread.php?9245-Cause-of-unresponsive-sluggish-keys-on-G74 discusses how to shim problem keys for better performance.
G74SX-A1 - stock hardware - BIOS 202 - 2nd Monitor VISIO VF551XVT