Yeah going single speed is pointless here. A single speed freewheel is a freehub contained in the mechanism. Also, if you went SS, you could just use your current RD for a chain tensioner.

Going fixed for the winter would require chain modifications. Basically just use two chain connectors and then you can remove a section of chain for fixed and add it for geared. For fixed, just bypass your RD altogether and make sure its out of the way. (via shifting)

The reason to go fixed is because there are no moving parts to freeze up or break. You also get insane amounts of traction control from your legs since you can instantly feel the wheel slip and just ride on the edge of grip the whole time.

As for a wheel, I doubt you'll find a wheel with a cassetted hub and a fixed threadup on the other side without having something custom made. So I wouldn't get into that too much. Getting a nice rear wheel is a possibility though.

@ MArio... yeah, thats an Easton hub.

if you want to go SS (keep in mind SS is not the same as fixed), but should you choose to go SS, I grabbed a crappy full squish frame from a dumpster that had a SS chain tensioner on it.  It is a pretty nice aftermarket one, but I haven't pulled it off to determine how operational it is, but it seems to be in pretty nice shape.  If it works and thats what you wanted to do, ill just give it to you

Remember though, that this will not solve the problem of the paws on the hub not engaging.

ha, ha, Dave. As you were typing your second message I was typing mine. Check the similarity: "That's actually nice free hub. You might have only two powel. Also there might be springs instead of steel leaves." Great minds think alike, right,ha,ha.

Oh no... thats just the pawls inside the freehub body sticking. Its a pretty common problem on lower end freehubs, and it may just need to be disassembled and cleaned. The reason that the derailleur is skipping is probably because you were inbetween gears, or (more likely) your derailleur hanger is misaligned. The misalignment is pretty common on big box bikes... they'll align it so that it runs very smooth in the forward motion, because it compensates for the crappiness of the rear drivetrain on lower end bikes, but this causes it to catch when pedaling backwards.

Things you can try:

1. Bang on the hub when in the field and you may just knock those pawls loose.
2. Ride fixed gear in the winter. Not only is this a big reason why people do this (less to go wrong) but you also get INFINITELY better control.
3. Buy a new hub or wheel
4. Do a total disassembly and clean and relub the internals of the freehub body.

I assume (no offense) that this is above your paygrade, but if you want to look into whats involved with the process, you can look in our resource thread at both Sheldon Browns website and the Parktool website. Sheldon will have lots of details, and park will have a how to.

In the meantime, here's a pic to sort you out.

Well, it might required some specila tool, or it might need just an allan wrench. There is a lot of different ways how companies mount the free body  hubs. Your best bet would be to take it to SBS. Is it really cold today/yesterday? By the way, I would say you were more dead in the snow/ice, than dead in the water 

Yeah... bottom line is that shit freezes.

I gotcha, I had to go read the post again and see that it happened when he was coasting too.

This happened to me one or two days before break...if it doesn't happen all the time, I wouldn't worry about it.  It's up to you to determine how much of an annoyance it is.

Mario, you don't think a frozen link or two running through the dérailleur would cause the same thing?  I only ask because it happened shortly after he lubed everything.  I don't know if the grease would freeze up unless it was really cold that day, but maybe your links wouldn't freeze up unless it was really cold either.