Actually skinning is bugged right now. Even while skinning gray beasts, you will get skill ups at the rate that you do with green beasts. It's supposed to be fixed in 4.2, so take advantage of it now while you can. I learned this recently when I leveled my DK's skinning with my druid's leatherworking.
I honestly have no idea why your tradeskills would stop skilling up at such a random level though. I'd submit a ticket and see if a GM can help you figure it out.
Edited, Jun 14th 2011 10:02pm by PigtailsOfDoom
Guild Wars 2, Crystal Desert server:
Inga Freyasdottir, lvl 40 Norn Mesmer
Deathbringer Kaami, lvl 16 Asura Necromancer
Popina, lvl 15 Asura Elementalist
Althaia Willowbark, lvl 7 Sylvari Engineer
Maeve Amnell, lvl 4 Human Guardian The MMO-Zam's FB group.
Please message me first so I know who you are.