My Knobs are Falling Off!

Once a project gets up to a moderate level of complexity it starts happening.
PLugins lose some of their GUI components. With high quality plugs like UAD it actually looks like something fell off, exposing the panel beneath. T-Racks Limiter just has a blank look.
The most annoying case is the Line6 PodFarm, which shows just an empty window frame, making it completely inaccessible.

Any rhyme or reason to why / what / when etc etc ?
I have 5.5.3 - are things any better in 6?

Which OS? If Mac, try setting colors to millions instead of thousands.

sorry, left out some important details.

WIN XP SP2 , with dual monitors (26" & 22")

What’s the memory usage of the problem project? How much RAM is installed on the system?

The memory usage is getting up there, last time I looked it was a little over 1G (thanks to Superior drums and its Still too early in the mix to freeze it)
The system has 6 GB of physical memory even though its still 32 bit Xp so its limited to 4 GB.
cubase cpu meter is only showing ~35%

Specific numbers. Start-Run-msinfo32 to get the available RAM #, Task Mangler to get Cubase RAM usage.

Meter in Cubase is the ASIO meter, has nothing to do with CPU.

I’ll do msinfo32 tonight.
Last night task mangler showed cubase at 1.1gb with 1.5 gb still available.

Is there a limit a one application can access? (One time I had other samplers also load and the memory was up to 1.5 Gb and then cubase was completely gummed up.)

Then things got even more interesting with hard cubase.exe C++ crash, so it was time to go to bed.

Some 32 bit Windows can only actually use ~3GB(depends on MOBO/Chipset) of the 4GB it recognizes and the 32 bit applications can only address up to 2GB on a 32 bit OS. Some of that 2 GB for the application may be virtual memory on the HD which may be slowing Cubase down and causing problems.