Some of you probably already know this, but for those that dont...
If you use the MAME arcade emulator regularly, be aware that all games using .CHD files (Capcom CPS3, Seibu SPI etc.) have had a major revision in version 0.145.
This means that your old ROMs will not work with this version onwards.
Please either update your sets manually, or make sure that any .CHD files you download from websites are clearly marked as 0.145 compliant if you are running later builds to avoid any disappointment.