DELETE Query On Windows Vista

I am having trouble with 3 delete queries in my c# application, two other Delete queries run fine. All the Delete queries run fine on Win XP, just not in Vista(Vista's User Account Control off). Here is the simple query
DELETE FROM [tableName] I get error SQL Execution error 3640. I get this error whether I am debugging in msvs2005, or running in the Query Designer or if I just run the application outside of msvs2005.
I can get a Delete Query to work if i use the key columns like
DELETE FROM Horse
WHERE (CODE = @p1) AND (Stable = @p2) AND (HorseName = @p3)


Hope some has an idea


If not is there any other way I can delete all rows from a data table?