Designs targeted to Cyclone III devices may not meet timing when the skew optimization option is turned on by default.
This issue may affect variations in designs targeted to Cyclone III devices.
Turn off the skew optimization option by adding the following assignment in the Quartus II settings file (.qsf):
set_global_assignment -name ENABLE_BENEFICIAL_SKEW OPTIMIZATION
This issue will be fixed in a future version of the Triple-Speed Ethernet MegaCore function.