I agree with the other posters that the Viking might just need a good tune up. I have that same machine and don't have those issues. I do piecing, garment and home dec sewing on it with no issues whatsoever. Good luck with your quest for a different machine though.

How many machines does anyone NEED! One.

How many does anyone want? As many as you have money and room for!

I have a Viking Lilly 550, a babylock serger and an old Kenmore machine. The old Kenmore was just given to me, so I am not sure how great it works. I use my Viking for everything, and I do sometimes make clothing. I love it. I need to play with the Kenmore and see how great it works. It helps me to have an extra machine for days my daughter comes for sewing days, and then she doesn't have to bring her machine.

I get my 'bargains' at garage sales, from craigslist, and/or eBay. I personally prefer pre-1980 machines. Newer machines may have plastic or nylon gears which don't last.

Well I did find and buy a 1954 Singer 201 as a second primary straight stitcher. These certainly are beautiful, quality, well-made machines--smooth and quiet. The 201 is in great shape, and I am still working on its restoration. I have even replaced the "Bakelite" original pedal with an electronic version to gain more control and to avoid pedal heat-up during FMQ. It sews the same hems (french seams and all) like butter that the Viking 750 balks at and sews so poorly. I am going to have the Viking serviced, but I spoke again to the lady whom I bought it from she said that Viking resolved the problem of thick intersecting seams with the included "hump jumper." She also assured me that it sews the same as it did when new. She had previously told me that it had been serviced just before she purchased her new machine. It had then been stored a while before she decided to sell it.

On another note, I test "drove" the Bernina 550QE. To push its limits and see what it could do, I sewed a french seamed, double turned hem piece of canvas on it. I was shocked and impressed to see it sail right over that seam!! The stitches got a wee bit smaller, but not really noticeably. I think I found my one machine that can do it all (for me). But I am in sticker shock and don't know if I'll ever recover!

If I ever do recover, I might just buy it and sell the Viking. I think I'm getting too attached to the 201 to sell it though...we'll see.

Thank you all for sharing and helping. I'll update after the Viking gets serviced, and of course if I end up buying the "Nina."

My answer is yes different machines excell for different tasks. My Pfaff that has the IDT (built in walking foot) is so wonderful for regular sewing, piecing quilts and stitch in the ditch quilting. However my Viking D-1 is an embroidery machine but has wonderful built in stitches that are great for quilting and deco sewing that the Pfaff doesn't do. Also the D-1 has a walking foot but requires you to put in a different shank to install so takes a little time to adapt. I love both of them.
I have never traded a machine in and have kept them all including the old Bernina in the red case that I let the grand kids sew on. Plus three old singers.

My Viking has been serviced. It's performance is better--no longer makes noises nor does the light fade in and out when going over seam intersections. The piercing power is good now. But it still makes small stitches when going over seam intersections. One example is an eight triangle pinwheel using regular cotton quilting fabric. This seam is not bulky, but is multi-layered. It is not really a "hump" and too flat to use a "Hump Jumper." It seems like a "feed" issue. Is this common with most (brands) of computer machines? What about those of you who own computerized Vikings--do you have this problem also?

Is there anything that can be done to correct this problem?

Some newer machines need a little plastic booster plate to put in front of the thick seam to help the presser foot climb up the thick layers. I bet this is all your Viking wants....a little boost!