PWM signal problem

Daixiwen, definitely is not VHDL code. I tried different pins like 41, 144 but the same result. Is good to know that variables causes non-deterministic behaviour - elegant explanation.

batfink, I checked the soldering, it is Ok. Normally, I use signals, but this is just a desparate try of using something different when ran out of idea what is wrong.

Now I wonder if Cyclone II - EP2CST144C8 needs special configuration in Quartus. Looks like it can't make low frequency pulses in my case.

Also how come that I'v got fmax lot higher then what was requested in the configuration. Say may physical clock runs at 25 Mhz, but I see actuall fmax 180.28 Mhz in Timing Analyser.