I had the same problem when I moved four blogs over to WordPress from Blogger. It was a nightmare, and still is, actually.
When I moved everything over, I did make full copies of everything, including saving the actual coding from all the pages in the blogs as text files. Yes, it was a pain, but after seeing things weren’t importing properly, at least not from my perspective, I took to fixing the issue in a radical way.
What I did was nab the actual code for each post, dump it into a text cleaner, eCleaner, and strip out all the links, coding, and just ending up with the raw text for each post.
In WordPress, I simply went in, pasted everything one-by-one, editing the date to display the original (actual) date of publication, as well as time, and uploaded it to the new blog.
No, it shouldn’t be that had to do something, but it seems it is. That’s what happens when everyone doesn’t follow the rules, when there is “proprietary” and “custom” coding involved, and you try to move to a different platform.
As far as eCleaner, it’s a great tool. It’s freeware, was developed by someone named Steve Chin, according to the copyright information, and he had a site at Tripod.com where he hosted it when I found it back around 2001 or so. I have been using eCleaner 2.01, but just found that the last version was eCleaner v.2.02, and you can still download it from PC World.
To use it, simply go into the preferences section, tick off the things you want stripped out, such as all the “>” if you are wanting to use something from an email that’s been forwarded at least 15 times, if you could all the “>>>” in the email that you received. Then, in the GUI, simply paste in the text you want “cleaned,” hit the smily face, which is the clean now command, and voila, it’s all done. Copy and paste to your new application, or save it to a text file. That’s all the training anyone I’ve told about it over the years ever needed.