Greetings sages!

I have sent a friend 32 meg to replace his 8meg already existing in a 1995 486DX-80 Win3.1 machine. He installs the chips and BIOS reports new amount correctly, but Windows will not run (he says it just gives him some weird video pattern and hangs). He can put in one or both or move them around but results are no different. Luckily, he can take them out and replace them with the old chips and everything works. The new chips are 16meg 72-pin (same as old), but are not matched. I tested them on a Win98 machine before sending them and they worked fine, Windows ran fine. Any ideas? Does Win3.1 somehow remember the initial amount of memory and not allow additional unless one knows the secret? Best guess so far is the chips must be exact matches. Any help most appreciated! Cheers, Joel