comparing gry with pir

Does anyone have any thoughts on why there is such wide difference in the current valuations of GRY and PIR?

GRY’s enterprise value is currently about $6m (mkt cap $58m and cash equivalent of $52m).
PIR’s enterprise value is currently about $330m (mkt cap $376 and cash $46m).

Sovereign risk is similar (Burkina Faso vs Mali).

The resource size and grade of their main projects (GRY - Banfora, PIR - Fekola) is not markedly different:

Using a 0.9g/t cut off for GRY’s Banfora project, measured is 0.26m oz, indicated is 2.45m oz, inferred is 1.04m oz – TOTAL 3.73m oz at 2.0 g/t.

Using a 1.0g/t cut off for PIR’s Fekola project, measured is 3.16m oz, indicated is 1.48m oz, inferred is 0.5m oz — TOTAL 5.15m oz at 2.4g/t.

Clearly, PIR has far more of its resource in the ‘measured’ category. However, as at June 2012, none of the Fekola resource was in the measured category — it was all indicated and inferred, and has been reclassified since then.

Most of GRY’s resource is shallow, between 0 and 150m. Both Banfora and Fekola appear to have considerable scope for resource expansion.

Any thoughts on why there’s such a marked difference in valuation?