Instead of searching the web, you may want to ask the RAM Megafunction User Guide. It tells:
--- Quote Start ---
For the Stratix and Cyclone series of devices, only synchronous RAM is supported. For other devices, you can use synchronous or asynchronous single-port RAM.
--- Quote End ---
You have manually instantiated a ROM without a clock, or in other words, an asynchronous ROM. But it's not available with Cyclone II and any other newer FPGA families. By implementing the ROM through the MegaWizard, you can only choose port and parameter combinations, that are supported for the respective device family.