I can see the current collation for my database but I suspect that certain columns may have a different collation. How can I check this please?

Look at the syscolumns table in your database, there's a collation column so you can easily test this to see if any columns aren't the default collation. (Use OBJECT_NAME(id) to see which table the fields belong to.) Something like this should get you started
SELECT OBJECT_NAME(id) AS ObjName, [name], [collation]
FROM syscolumns
WHERE [collation] IS NOT NULL

Alternatively you can use EM to script all the tables (All Tasks > Generate SQL Scripts) and examine the script by eye.

hth
Phil

Thanks Phil, that worked for me. (I couldn't find it in the Sybex certification crib books :-)