If the problem occurs on multiple different players, both standalone and also DVD-Rom drives in a PC, then this narrows the focus, at least somewhat.
Some of the more common causes-->
-Using too much compression. A possible test to see if this might be the case -- check a disc which was backed up from a single-layer original; in other words, check a disc where you used NO compression at all. See if that type of disc exhibits the same symptoms. If it does, then your problem is probably further down, and your problem is probably NOT due to the amount of compression you have been using. If, however, a "non-compressed" backup plays fine with none of the skips, and jolts that you described, then I would consider reading up some on how to avoid "overly-compressing" those backups. You can consider getting rid of some of the fluff, and extras (foreign language sountracks, subtitles, directors' commentaries, deleted scenes, previews of coming attractions, FBI warnings, "making of" documentaries, etc.) You can also consider dumping closing credits (a bit more drastic, but for some this is not a problem). You can also consider splitting such dual layer original DVDs out to two discs (this is my preferred method), so you do not need to use any compression at all. Ever.
-Lousy media. Lousy media can result in lousy burns, and is without a doubt the most common cause of a lousy burn. Consider whether you have been buying your media based mostly on price, or whether you have been deceived into believing that a particular brand or type of media is fine, when it is not.
-Burning too close to the outer edges. This is actually related to the problem above (lousy media), in a way. The "sensitive" spot on most of the mediocre media or fair media or lousy media or awful media seems to be the area at the outer-most edges. In many cases, this is at the very end of a movie. Not always, though. Sometimes, the outer edge is where some extras were placed, so people mistakenly assume that skipping and jumping during extras is not due to an "outer edge problem." And, with dual layer discs, that laser is going to be near the outer edge twice... once on the first pass, and once on the second pass. The outer edges on a lot of media is where the dye tends to "run" or "seep" or not be sealed well, which can cause some problems, reportedly.
-Older firmware, in need of updating. Related to the above. Many of the manufacturers recognize that their drives work with the media on the shelves at release, but six months later there are now 50 or 70 new types of media out there, and some of them demand a slightly modified "writing scheme." So they will often field the complaints from those who made lots of coasters, and then "add" the new write scheme to the firmware so it can be used with those new discs. Solution: do a search, and see if you are operating on the latest firmware.
-Multi-tasking, especially during an actual burn. We have all had "regular" software lock up, and freeze, and had to wait for some sort of loop to cycle and wait until (sometimes) the computer returns control to us. DVD burning is INTENSIVE. It is about equal to the most intensive task a normal consumer tries to do on a home PC. Yet, I still know people who try to surf the net while they burn, or work in Photoshop on a cover for their DVD backup, or who let file-sharing continue in the background while they burn, or who visit this forum while they burn... you might get lucky, and the whole process might not quite come crashing down, but those "handshakes" between your processor and the software and the computer "bus" and the DVD burner might time out enough that "skipping" occurs, causing the laser in your burner to actually burn in "starts and stops," or in a "herky-jerky stuttered" manner. Obviously, this could cause lots of later issues. You may end up with a "complete" burn, but one in which the laser has produced lots of minor errors.
-The DVD burner is going... something mechanical, or the laser wearing out, perhaps, or the laser is no longer focused as it should be, or as precise in placement as it should be, causing errors later on when you try to play. This is probably the LEAST likely occurrence of this list, but it does happen, so it belongs on this list.
There are certainly other causes, but none that I can think of that are actually very likely at all. So, certainly, start with the six items listed above, and check each.