This is a known issue with Epson printers...
I've seen this problem - dark prints with a calibrated LCD - with a client's Mac/Epson 3800 and could not resolve it. As it turns out there is bad bug in OS X. Bad enough that Adobe has posted a TechNote with a screwy work around:
http://www.adobe.com/cfusion/knowled...fm?id=kb400878
Strange thing is the issue affects some users and not others. For instance my Mac/Epson 4800 prints dead on.
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