From Barrie Selack:
WebSphere 6.1 does not like a variable in an attribute which is a dynamic attribute.
This means files such as
<aui:input fieldParam='<%= "emailAddressAddress" + emailAddressesIndex %>' label="email-address" name="address" />
cause compilation errors in WebSphere 6.1. I tried even making the variable a single variable (not a concatenation), but the only thing that WebSphere 6,1 accepts is a string. This is only for dynamic attributes. Normal attributes have no issues.