Repro Steps:
1. Create a custom report via the report wizard against accounts.
2. Open Outlook 2010 with CRM client configured with Rollup 11 (might need to be over IFD, unsure).
3. Select (single-click) an account from the active accounts list view (do not open the account).
4. Run the custom report against the account from the list view.
5. Instead of getting a report, you receive "An error has occurred."

Repeat the same steps using the web client, or by double-clicking the account to open the account form, and everything works fine.