Memory Banks Filling certain memory banks with older 32 pin SIMMs can cause other banks to switch off, thus complicating the process of working out which configuration is acceptable, if in doubt get the manual and motherboard before the memory. Prepare to solve problems. When I opened the box containing the P133 which is running in the computer on which I am writing this page, I noticed that one of the pins was bent. Working out how to straighten it when I didn't want to actually touch it was a little tricky. The pin had clearly been bent, by someone attempting to fit the processor the wrong way around into the ZIF socket.
Suppliers sell used kit.
If you are receiving un-boxed kit, check it out very carefully. Suppliers re-sell returned goods. Other times they re-sell so as to delay you, allowing them time to actually get the stock which they were supposed to have when they sold it to you. Also, I am sure that pentiums could be sold as higher models than they actually are due to their ability to be overclocked so easily. A squeaking noise from a P133 system turned out not to be the main PSU fan, but a warning that the processor fan was about to stop working.