Are both machines running the same version of Windows, SQL Server, Service Packs, AND HOTFIXES/PATCHES?

>HI
>
>I have a c# CLR that I'm using to decrypt bank sort codes and account number.
>
>I've has an error that caused SQL to restart
>
>A fatal error occurred in the .NET Framework common language runtime. SQL Server is shutting down. If the error recurs after the server is restarted, contact Customer Support
>
>This seems to occur when I use the CLR in a table update rather than just decrypting one row.
>
>so
>
> update integra_live.dbo.xmasall set sortcode_decrypt = dbo.fn_RMB_RemoveCharacters(dbo.fn_RMB_bank_decrypt([Sort Code],@decrypt_key), '^0123456789') where [DD reference] = 'RWM000196'
>
>works
>
>and
>
> update integra_live.dbo.xmasall set sortcode_decrypt = dbo.fn_RMB_RemoveCharacters(dbo.fn_RMB_bank_decrypt([Sort Code],@decrypt_key), '^0123456789')
>
>fails
>
>any ideas why there should be this differnce
>
>as an extra confusion bith statements work perfectly on my development server.
>
>Thanks