Hi Everyone, First - I must identify myself as the technical manager at Biotest in the US. I really appreciate Trektech working on this problem with us, as well as all your ideas for possible reasons for the problem. Trektech is seeing these crystals regularly, however there was only one lot where another account saw them as well. With such a rare occurrance (one customer/set of cells per a couple of hundred users and even more sets of cells) trying to do a root cause analysis has been very difficult. Since the crystals only appear at her site after 3 weeks of product use, our testing at different temperatures etc - takes at least 3 weeks . I do understand the frustration, because I'm feeling it too. (I don't usually answer these!) While our investigation team/QA/QC is working on this, does any one have any other thoughts on what might be causing this? Especially at just one site routinely? Thanks!