Managing memory (freezing does not work)

Hi,

I am using 32-bit Cubase 6 AI on WinXP, the performance is very good as long as I don’t
use multiple instances of Amplitube plugin.

Amplitube hogs around 300 MB with a single instance. After I insert a fourth instance,
Cubase crashes. Here is the problem:
freezing does NOT actually free up any memory, I observed that using Windows Task Manager.
Is there a better way (than to export an audio mixdown with pooling and then disabling the effects
on original track) to free up memory temporarily?
Shouldn’t there ideally be an easy way, its such an important issue, and from a developer’s
perspective, perhaps not very hard to implement?

Regards