This Knowledge Base article actually got published a week or two ago but after looking through the site it doesn't look like I posted it here. Just as an FYI, here's the symptom and cause and a link to the KB so you can read it in it's entirety straight from the source:
If System Center Virtual Machine Manager 2008 (SCVMM) has PRO integration with Operations Manager enabled, in certain situations the administrator console may take a long time to load and the memory footprint of vmmadmin.exe may become excessively large.
This can occur if there are too many PRO tips in the SCVMM database. During the initial load of the SCVMM administrator console we also load all PRO tips into the UI, both active and completed, thus potentially causing this issue.
We have a script to groom the PRO tips database, thus resolving the issue, in the KB article below:
2027023 - The System Center Virtual Machine Manager 2008 administrator console may take a long time to load
J.C. Hornbeck | System Center Knowledge Engineer
<p>We always have claim from customers using SCVMM about the vhd deletion when you disconnect one virtual machien hard drive or when you delete one virtual machine in the console.</p>
<p>this behavior is not the same compared to Hyper-V management console and competitor console. </p>
<p>The Team wrote : "it is by design", but could you provide a way to protect vhs from deletion on some virtual machine.</p>