Digital BW, The Print

Hello,
I also posted this question to the Piezography group. I apoligize for the 
redundancy but I know this is a bigger group and I am hoping for a quick 
solution.

I just loaded up an Epson 7500 with selenium toned piezo ink. I am using 
IP5.6. And the ink I am using was purchased in July -I wanted to use up most 
of the OEM color ink in the printer since I have access to an Epson 9500 with 
the same inkset at my institution. I followed all the updated instructions, 
loaded the flush cartridges into the printer yesterday afternoon and loaded the 
Piezo ink cartridges today. I pulled each one out for a reset and then 
performed an initial load of the ink. My first test print looked good but my 
second larger print came out with a terrible yellow-green tint, as has every 
print since. I also tried to run the flush image that came with my old CIS 
system to no avail. 

I think two things could be wrong. When I ran the first flush my yellow cartridge 
light began to flash by the end of the cycle. The flush cartridges were bought 
this week at IJM and I had to break off tabs to get them to fit into the 7500 -its 
possible this cartridge might not have set correctly and therefore not fully 
flushed the yellow. Why would the first print look neutral and from neutral 
progress to a not so slight yellow/green tint? The only other possibility I can 
imagine is contaminated, badly labeled (maybe one or more cartridges are 
not really SL), or simply bad ink. I will try and find a CMYK image and run it 
with a color profile to identify if one ink is tainting the whole process. Any other 
words of wisdom? I do not have an owners manual can you purge one ink 
without dumping the rest? Jon is it possible to have a bad batch of ink? Since 
I am familiar with the selenium set I know this is not how it usually looks. 

Thanks in advance for your help.

Alan Labb