I don't understand it....

When ever I use a codesnip from someone it never work on my test board. I always have to slow down the timing. If I want to have nice digital curves on my oscilloscope I cant change a pin faster than 200us and that's only 5 kHz. Is it me or what is wrong. My system is based on
Pic16F84-04, 74HC164 and 74hc-something-8bit-latch, LCD HD44780 and a LM/DS75

Regards
Benjamin Petersen