India's infrastructure boom is seeing some cracks in the wall. BHEL says that rising input cost and capacity constraints are hurting its margins. On the other hand ABB sees slower growth in power systems and products business and Siemens says that cost escalation in power project is hurting its profitability. Over last one month Sensex has gained nearly 9 per cent but BSE capital goods sector has underperform Sensex by losing nearly 2 per cent.