I've upgraded to the latest firmware (o02269, which, eventually, is a lower number than the firmware the printer had previously --> check with the remote panel and do not trust on the firmware numbers) and things with Mate seem to improve, althought I've to perform some more tests. I'll keep you informed.
Manuel, please do keep us informed about your findings.
Whether the print comes out of the printer more or less damp is not really the determinative issue. The determinative issue is what you see on the paper the next morning after the print has been allowed to dry. By then, the paper should be flat and the print quality should look much crisper and cleaner.
Eric and I both tested the same printer target file on our respective machines (3800/4800). (We do not live in the same cities, so we are doing this by email.) When we examine the prints under bright light, we can see traces of a mottly, greyish uneven splotchiness in the deep tones. This is the problem. The status of this issue as it has evolved between Eric and me right now is that the kind of effect he is observing in the dark tones on EEM coming out of his 3800 are similar (but perhaps more intense) to what I see coming out of my 4800. On examination of older prints I did NOT find this effect on prints from my previous 4000 using original Ultrachrome. This is mainly why we think it may be more related to K3 ink than to the printer model.
Interestingly, at least for me with the 4800, the angle at which the light hits the paper and at which you view the print determines whether you see this effect or not. It is there, but not equally bothersome at all lighting and viewing angles.
The reference to Epson is that I shall bring these target test prints to PSWorld in Boston next week and show them to people in the Epson Booth, and see what they advise about it.
Meanwhile I think it would be very helpful if 3800 and 4800 owners reading this thread could contribute their observations - not so much about the prints coming out of the printer damp, but whether or not the next morning you see what appear to be greyish or muddyish blotches in deep-tone areas of the prints.