Bug 146709 Dates still do not work from main report to sub reports...
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/util/ParameterValidationUtil.java
try
		{
			if ( DesignChoiceConstants.PARAM_TYPE_DATETIME
					.equalsIgnoreCase( dataType ) )
				return doValidateDateTimeByPattern( format, value, locale );
			else if ( DesignChoiceConstants.PARAM_TYPE_FLOAT
					.equalsIgnoreCase( dataType ) )
			{
				Number number = doValidateNumberByPattern( dataType, format,
						value, locale );
				if ( number == null )
					return null;
				return new Double( number.doubleValue( ) );
			}
			else if ( DesignChoiceConstants.PARAM_TYPE_DECIMAL
					.equalsIgnoreCase( dataType ) )
			{
				Number number = doValidateNumberByPattern( dataType, format,
						value, locale );
				if ( number == null )
					return null;
				return new BigDecimal( number.doubleValue( ) );
			}
			else if ( DesignChoiceConstants.PARAM_TYPE_STRING
					.equalsIgnoreCase( dataType ) )
			{
				if ( StringUtil.isBlank( value ) )
					return value;
				else if ( DesignChoiceConstants.STRING_FORMAT_TYPE_UNFORMATTED
						.equalsIgnoreCase( format ) )