Since an update from a very old version 5.4.2.2 to (a still old) 5.5.2.1 the Content Block will change any dubbele quotation mark (") in \"
That looks ugly in text, but the real problem is that links do not work anymore, because they turn into something like this:

http://www.mywebsite.nl/\"/subpage/\"...
It's not a theme problem, because a default theme does the same.

Any help highly appreciated, because this website is now practicaly unusable: the only links on the Homepage (sort of a portal) are in Content Blocks. So no visitor will get past the homepage.

Maureen