Such crashes are often due to bugs in SQL Server, and had you been on a fully supported version I would have to recommended you to open a support case.
There are a few more possible causes for a crash like this. One is a hardware issue, what comes closest to mind is a bad memory stick, so you may want to run memory diagnostics.
Another possibility is that you are using some external module that runs in-process and that scribbles the memory. This includes:
- Extended stored procedures.
- Unsafe CLR assemblies.
- Third-party OLE DB providers for linked servers.
- OLE objects invoked from sp_OAxxxx.