Hello,
Having the same/simmilar issue - i setup a clean WindowsXP install to try the VM system out but cannot remote access. As i couldn't remote access to carry out the installation, i installed it locally on my PC in virtualbox and moved the drive image over and imported this into phpVirtualBox.
This machine will boot and i can see the desktop in the preview box however if i click the remote desktop link i get the RFB 003.008 message in the browser. If i point remote desktop client to connect to the IP and port i get the error 0x1104. Ive also tried changing the port but i get the same error. If i try to connect with the VM not running it tells me the machine isnt running so im sure the connection is being attempted but is being refused somehow by the XP install or the phpVB app.
Other posts and online indicated to uncheck "visual styles" which ive done to no avail. Also there was mention of the Extension Pack not being installed, but as far as i can tell it is as supplied in the jail template.
As a final one, in phpVB i click on console, the browser tells me the plugin isnt supported - again online things point to the Extension Pack not being installed but i think it is.
So it looks like ive got my trial VM running but i cannot view its desktop or get keyboard/mouse input to it.
Any pointers would be usefull.