Major bug here guys. Any quest that gives out a free training session in a skill will bug that skill. You will no longer be able to raise that skill without using ` cheats.
I noticed it when I could not get my mercantile skill above 50. This happened after I did the Hackdirt quest and recieved free merc training. I have also done a fighters guild quest in which I recieved a free training in acrobatics. I jumped for about 10 minutes and my skill stayed at 23 with no visual progress in the skill bar.
Many people are experiencing this bug according to the Oblivion forums. (PC version, not sure on xbox)
I would skill the hackdirt quest until its patched. (Its in Chorrol, Seed-Neeus wants you to find her daughter)
As far as the fighters guild quest, it the Rat troubles quest and you can complete it, just when finished, turn in the culprit instead of taking her reward.
Vlan Jod'Rhazor, retired Imperial Adventurer
Reborn - Vlan Jod Rhazor II *sigh*