Please help me out with this problem:

I have just started daggerfall for the first time, and i'm trying to do the main quest, but i have a problem on the ''Morgiah's Wedding'' quest.

( http://www.uesp.net/wiki/Daggerfall:Morgiah%27s_Wedding)

I have delivered the note to the king of worms, and received his response letter. When i return to Morgiah however, i can't talk to her!
I can progress no further in the main quest... I have already reloaded a save (i saved just before i picked up the quest, in front of castle wayrest) and retried the quest from scratch, and the same thing happens!

Any tips? After playing Skyrim and discovering that earlier entries like Daggerfall are enormous, i was exited to play. I hope someone can help.

Ps:

Maybe the cause of the problem is that I start this quest on the merchant holiday ?(every thing 50% discount)

The only thing I can think of might be that you spent too long traveling, and she won't talk because you took too long. I don't think this sinks the main quest though, the quests are generally spread out based on the player's level.

I think i have found the cause: when i exit scourg barrow, the note of the king of worms is still in my inventory. BUT: after i have fast traveled, no matter to what location, the note just vanished from my inventory... any tips to keep the note from vanishing?

I just want to do the main quest...

Use an anchor/recall spell right beside Morgiah before you go to the barrow, and that might keep it in your inventory.

The letter vanishes because the time for that quest has elapsed (the same happens for every other quest item related to a timed task), so your best bet - as Shades said - would be to teleport yourself to Wayrest Castle as soon as you're done with the KoW.

Also, failing this mission pretty much puts an end to the main quest (you can still do the Orsinium quest, but you won't get the Lich's Soul one from KoW which subsequently blocks the final Totem quest).

Actually, you shouldn't have any trouble if you travel recklessly there and back; that's what I regularly do on that quest, and since on the first leg you're going from a city to a dungeon, your health and stamina should already be good and arriving at night isn't really a problem. If either of those is a concern on the way back, you can also travel recklessly to a nearby town and then cautiously to Wayrest. The recall thing works nicely as well, of course, but this is an option if you're not or you can't use magic.

THANKS, the teleport anchor worked. So you have to be damn fast then. I immediately traveled to the dungeon, got the note very fast, and traveled back, but using the cautious travel setting, I guess that took too long.

Yeah, it's pretty easy to miss quest deadlines if you're always travelling cautiously, since it can often take twice as long as it'd take by going recklessly. If you wish to fast travel somewhere and arrive during daytime, your best bet would be to use the "reckless travel" option to get to a nearby city/house/graveyard/whatever, and then use the "cautious travel" to reach your destination.

Also, there's no point in using the cautious travel to get to some places (dungeons, for instance).

Also for that trip, the "by ship" option would make it faster. You can travel by ship before you have one, it just costs more. I don't recall ever having the Morgiah quest time out, and I generally leave the by ship option in place.

You can also make a donation to the Akatosh Chantry (which happens to have temples in Wayrest), to get a blessing that lowers travel times.

Yeah... Unless you're a vampire, it's always best to Fast-travel "Recklessly", "Sleep at Inns" (Reduces time further... somehow), and "By Ship" if it's an option. It reduces the Travel Time from More than a Month(!) to about a week.