Can Virtualbox in Mint14Mate run Mint15RC?
I downloaded Mint15RC and burned dvd and tried installing it in Virtualbox on Mint14Mate. All it did was hang after telling to install. The DVD boots and runs as live. Never had problem installing live b4. Cant remember if RC Live DVDS run in VBox.

I have been able to run Linux Mint 15 RC and also install it on Virtualbox under Fedora. Cinnamon, of course, run with software rendering and as a consequence everything was a bit slow (as expected). No problems here.

Perhaps it's a problem with the VM? Enough RAM?

If you can point VirtualBox to the .iso file rather than the physical disc it generally works faster. might not help much in this case but it's worth a try.
There is no reason, in theory, that you can't run 15RC inside 14. Did you wait a while before deciding the install wasn't working? When you say it works as live DVD do you mean it works as a live DVD without VirtualBox?

Thanx! well I accepted recommended 256mb of ram on VBox setup but will try increasing....Have 8gb 64bit host

Just checked dvd integrity and it is good. 15 Desktop shows in Vbox and what I clicked on in menus seemed to work. Not exhaustive attempt tho.

First time I waited 30 minutes for it to get off the desktop screen after clicking install and do something. this time now it is acting like video weirdness is happening from black screen to odd ball patterns to desktop appearing all on it's own like it is possessed. I was able to click on install this time when desktop appeared as I had before minutes ago and cursor showed activity but stopped and would not start again

I thought I read somewhere that a lower kernel could not run a higher kernel?

Got an error but not sure how to attach screen shot:

My memory as in dementia is keeping me from being organized about this after a certain period.

Ah, 256MB sounds like far too little -- I would go for at least 1GB and probably 2GB "just in case" at least until you get it installed.
As far as I know VirtualBox presents the guest OS with a virtual x86 machine and hardware so the host OS is largely irrelevant. The only exception I recall being when using virtualization functions on AMD64 platform.

256 MB RAM is not going to cut it, I think.

Host is 64bit, Mint15 is 32bit, memory=1024mb, disc=16gb, 3D aceleration on. Graphical install just grinds to a halt and compatability mode gives me this message: [graphical interface not likely set up correctly].
"failed to start the x server your graphical interface. It is likely that it is not set up correctly. Would you like to view the x server to diagnose the problem?"
"x.org x server 1.13.3 release date 2013-03-07 x protocol version 11, rev. 0 Build operating system: Linux mint 3.2.0.19-generic I686 Ubuntu Current OS [I cant stay lucid enough to copy all this by hand sorry and it basically says nothing other than tell waht it is and not why its not working... do you suppose A4-3400 not supported here? It's working in Mint 14 MAte except for cinnamon... Cinnamon seems to have trouble with my configuration]" I pretty much loth cinnamon as much as Ubuntu Unity also.
System Build: TA75M board/A4-3400APU/8gb-pc3/24xDVDRW/AntecBasiq430w

Well just downloaded, burned, and installed and now updating Linux Mint15RC Mate. No hassles or error messages. Of course had to use torrents instead of Servers.
Cinnamon has never cooperated with me or my setups and neither has Ubuntu since Unity. It would be interesting to see how cinnamon works but seems too much Like Windoze.
Seems like the fraphic intensive misbehave the most!

Well, just to let you know. I have used as much as 4 GB RAM for my VMs to test GNOME-Shell, Unity and Cinnamon so that I have lesser lag/performance hit.

I am not a big fan of using 3D for first test on an iso.

As above noted, you should never need to burn a dvd for a vm. Just use the iso image. Much faster.

Ran across this while searching LinuxMint Forums:

"Cinnamon will run fine on VirtualBox, but make sure you have enabled 3D acceleration for the virtual machine and shared 128 MB of video memory. You can do so on the Display tab of the Settings for the virtual machine. Perhaps trying for the resolution of 2560x1440 is a problem, so trying something less if it doesn't work."

I use 16 gb hard drive space/256mb memory/and 128 video memory/ it's installing now with no hiccoughs. 3D might be required and serious video memory might be required also.
MY sesolution won't go beyond 1280x1024 and install just finished/login worked/and Mozilla FF opened. Soooooooo way toooo much video memory used for me since I can't see 3D!!!
Too much wast e of resources for functionality perhaps also. Not unlike 'Doze'

If you think about it there hasn't been a (mainstream) machine shipped in the last decade without some form of hardware 3D acceleration present so expecting it to be there isn't really much of an assumption.
That said, Ubuntu and its ilk are there to be eye-candy desktops for those wanting an experience like Windows or OSX. If you want something more "serious" then you can run LXDE, XFCE or one of the many window managers out there instead.

Not sure that is a requirement or just some forum advice. I tend to just try a distro without 3D to start. Then I see how it goes.

From the Mint web page for 15RC

"System requirements:

x86 processor (Linux Mint 64-bit requires a 64-bit processor. Linux Mint 32-bit works on both 32-bit and 64-bit processors).
512 MB RAM (1GB recommended for a comfortable usage).
5 GB of disk space
Graphics card capable of 800×600 resolution
CD/DVD drive or USB port
"

A vm would tend to use virtualized hardware for most of that.

3d acceleration doesn't have to be on to install. Also you are not limited to 32-bit installs.