This is a problem that has plagued me for a while now, and I have not yet found a solution. I'm not even 100% certain it is a linux problem.

I'm using Slackware 14 64 bit.

I run VirtualBox, XP 32. In this VM I use Cisco AnyConnect VPN Client (cause I can't get it to work under linux, so I use it in the VM - been doing this for years, works great). Once the VPN connection is established, I can access the remote network fine. The problem is that when I remote into a linux box, the capslock is stuck on. I remote into a XP box, no problem, it is just when I remote into the linux box that the capslock is stuck. I can't for the life of me figure out how to get this to work. Anyone have any ideas/suggestions on what would cause the capslock to be stuck on only when I remote into linux boxes?

In case my posts don't make sense, here is the current config.

Host machine: Slackware 14 64 bit.
Guest machine: Windows XP running in VirtualBox on the slackware host.

If I remote into the Slackware box via tightvnc, and then start up the guest vm and start working in the vm, sometimes the caps lock and sometimes control key stick, and can't be unstuck. This makes it impossible to control the VM. Outside of the VM everything is fine, but at this point I can't use the VM. Rebooting the VM doesn't help. Rebooting the linux box does.

If I'm at my desk instead of remoting in via tightvnc, it works great, I work like this all the time. But if I remote into the linux box via tightvnc, sometimes the caps and ctrl stick when using the VM.

So there is some weird combination of using tightvnc to get into the linux box, and from there running the vm. The only solution so far has been to reboot the linux box.

What about using an other VNC such as TigerVNC?
And what about accessing the VM via VB's RDP?
Just my 2 cents.

Trying another VNC is next on the trouble shooting list, as this only happens when I VNC in. If it's the tightvnc client and not the KDE desktop sharing server (which I'm currently using), this might work. I'm also wondering if tightvnc's own server might help instead.

Hmm...never thought of using RDP to get into the VM instead of going through the linux box. I have the network on the VM set to NAT, I may have to set it to bridged so it is accessible from outside of the host. I wonder if I can forward the rdp port from the VM to the host instead? I currently have ports 1433 (mssql) forwarded to the host so I can access mssql from other machines on the network, and that works fine. Definitely going to give this some thought and play with it, that is a most excellent idea!

VB's RDP works via a port on the host, not the VM. So whether or not the VM has NAT is irrelevant.
Actually you do not need VNC at all in this scenario. I would telnet/ssh into the remove box and issue a vboxheadless for the VM therein. And then I would use VB's RDP to access the VM.
As an alternative you could start an RDP or a VNC server *in* the VM. Of course that VM should not be NAT then.