Wow. Big step. Which SQL Servers are you using? Were you having performance issues with 32-bit? Moving to 64-bit SQL can be beneficial, but it can also give no performance increase and cause problems. Is your processor fast enough to handle 64-bit SQL.
There can be some issues with some 32-bit programs working with 64-bit SQL. Especially issues with 32-bit drivers. I am surprised that AC support did this. I will be more surprised if they can fix it.
My recommendation would be email my friend who is Microsoft certified in ALL versions and all architectures of SQL. Many times, it is necessary to map out the exact plan of changing 32-bit instances to 64-bit. I will forward your question to him and see what he says.
