Spring support: good configuration code highlighted red!

I noticed this in IDEA 7.x, and I see that the behavior has not changed. IDEA does not recognize the following Spring definition:

<context:property-placeholder location="/WEB-INF/config/.properties, classpath:*.properties"/>

Spring allows listing the locations of the properties files as comma-separated paths, but IDEA highlights the location string red as an error. It accepts a single entry only. Why?