Disappearing plugin graphics?

When I max out a project with effects I start losing the graphics of the plugins [ a blank window appears] until eventually Cubase crashes.
Could somebody tell me exactly what resource I am using up and if there is anything I can do about it?

I am using Cubase 6 32bit on Win 7 64bit platform

TIA

Probably memory related?

Go into task manager and have a look!

Yep, I often used to get that before I upgraded to Cubase x64 and 8 gigs of RAM…

Mauri.