Hi NVP,
Can you please provide some additional information about the CRM 4.0 to 2011 upgrade? What Update Rollup were you on in 4.0, and which Update Rollup are you now on in 2011? Also, were you using any language packs in 4.0 that are not present in 2011 and do you have any plugins that would affect the Contract entity?
In any event, I would recommend enabling tracing while either of the System Jobs is executing and post the Async trace files here, as they will provide a better understanding on what is happening in the platform. Here are instructions for enabling tracing:
1. Open Registry Editor (regedit) and navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSCRM
2. Add or verify the string value registry key "TraceCategories" and modify its value to *:Verbose
3. Add or verify the DWORD registry key "TraceCallStack" and modify its value to 1
4. Add or verify the DWORD registry key "TraceEnabled" and modify its value to 1
5. Add or verify the DWORD registry key "TraceRefresh" and modify its value to a different value than its current value (1 to 2, 3 to 4, or even 5 to 1)
6. Once all of the registry keys are in place, reproduce the error or issue
7. After the error or issue has been reproduced, return to Registry Editor and modify the TraceEnabled value to 0 and TraceRefresh value to a different value than its current value (1 to 2, 3 to 4, or even 5 to 1)
8. All trace files will be found under the Trace folder in your installation folder (default is C:\Program Files\Microsoft Dynamics CRM\Trace), and these can be opened with your preferred text editor