NeedIndexError suggesting index that already exists

[Klaas Pieter Annema]

After running a query on the dev server it shows the following error:

The following index is the minimum index required:

- kind: Product

  properties:

  - name: nameQuery

  - name: storeKey

  - name: tags
  - name: variationMaster
The suggested index for this query is:
- kind: Product
  properties:
  - name: storeKey
  - name: tags
  - name: variationMaster
  - name: nameQuery

This is the relevant part of my index.yaml:

- kind: Product
  properties:
  - name: storeKey
  - name: tags
  - name: variationMaster

  - name: nameQuery

The index that dev_appserver.py suggests exists already, additionally adding the minimum required index doesn't solve the problem. Before I file this as a bug I want to make sure I'm not missing something. Any ideas on what I could be missing or how I can resolve this issue?

- Klaas Pieter