RAM usage higher on project reload

Hi,

I'm using Sonar 8.5 32 bit on Windows 7 (I'd like to use Sonar 64 bit but thats a different story) and I have a project that I was doing some mixing on which uses lots of instances of Nebula.

I was working successfully in the project, then closed it down for the day, come back the next day, open up the same project and all of a sudden its using more ram than the previous day - pushing me over the 3gb limit. 

I'm 100% sure it hadn't reached this limit the previous day because I was working in the project and using it successfully and since I started using Nebula I have been keeping an eye on my ram usage. When I closed the project down the previous day it was using around 2.7gb ram.

I've also tried loading the project up within 64bit Sonar however this does not work - I've opened up in safe mode and I can get the project to work if I only allow instances of Nebula to be initialised and I can get it to work if I allow all other plugins to be initialised but I can't get it to work if I allow it to open all plugins - bitbridge just seems to sit there (for ages) and doesn't do anything.

So my question would be, how is this actually possibly? Why is my project all of a sudden using more ram than when I last saved it?

Thanks
Alex