Index: LookupEnvironment.java
===================================================================
RCS file: /home/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/LookupEnvironment.java,v
retrieving revision 1.54
diff -u -r1.54 LookupEnvironment.java
--- LookupEnvironment.java	7 Jun 2005 16:46:54 -0000	1.54
+++ LookupEnvironment.java	21 Jun 2005 17:41:22 -0000
@@ -470,11 +470,15 @@
 	// resolve any array bindings which reference the unresolvedType
 	ReferenceBinding cachedType = packageBinding.getType0(binaryBinding.compoundName[binaryBinding.compoundName.length - 1]);
 	if (cachedType != null) { // update reference to unresolved binding after having read classfile (knows whether generic for raw conversion)
-		// TODO (kent) suspect the check below is no longer required, since we should not be requesting a binary which is already in the cache
-		if (cachedType.isBinaryBinding()) // sanity check before the cast... at this point the cache should ONLY contain unresolved types
-			return (BinaryTypeBinding) cachedType;
-
-		((UnresolvedReferenceBinding) cachedType).setResolvedType(binaryBinding, this);
+		if (cachedType instanceof UnresolvedReferenceBinding) {
+			((UnresolvedReferenceBinding) cachedType).setResolvedType(binaryBinding, this);
+		} else {
+			if (cachedType.isBinaryBinding()) // sanity check... at this point the cache should ONLY contain unresolved types
+				return (BinaryTypeBinding) cachedType;
+			// it is possible with a large number of source files (exceeding AbstractImageBuilder.MAX_AT_ONCE) that a member type can be in the cache as an UnresolvedType,
+			// but because its enclosingType is resolved while its created (call to BinaryTypeBinding constructor), its replaced with a source type
+			return null;
+		}
 	}
 
 	packageBinding.addType(binaryBinding);