HD Install :: RAM Problems

I'm running a Frugal install of DSL on an old AMD k6-III. I recently found a compatable 128mb stick of ram in an old comp. i had sitting around a swapped it into the dsl comp, replacing a 64mb stick. Now, whenever I download a large file or start using a large amount of the ram, DSL completely freezes. I tried substituting the old ram back in and I have the same problem with it. I did not have this problem before trying to swap the ram. I have tried unplugging the box and holding the power button 5 sec to clear the nvmem.

original here.