I put the new 128MB module into my LC 575 and it registered fine, so I'll post the link if anyone else is interested. It's a darn good price, but there are only three left: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180448534803

$15, and free shipping. Hard to beat for a 128MB 72 pin SIMM. It came in a sealed antistatic bag. Looked new to me, or at least well-refurbished.