On 32 bit OS 2GB is max possible memory for a process and we have seen the Shareable use up a large portion of this. We are still investigating why this happens so would be interested to know the results on your system.
Also please include the Domino Version, OS Version and results of this command in the domino console:
show stat Database.*
Feedback response number WEBB7VQJH7 created by Corey Quinn on 09/09/2009