Don't use currency and variant types. Net will not support these types. Use decimal types instead of currency. Net will replace variants with support for object types. Check your arrays.
Net supports only zero-based arrays.
Change existing arrays to be zero-based to make the transition easier. Don't use default properties. Visual Basic 6 saves you time by letting you access the default properties for an object. In contrast, Visual Basic. Net requires that you explicitly define the property, function, or method you want to use.