What I too often find in translation memories are things such as this:
"You may wish to install additional software programs or hardware devices on your PC. Restart the PC after installation."
"Dopo aver installato un nuovo programma software o un’altra periferica riavviare sempre il computer."
That is, the Italian has turned two English sentences into a single Italian one, in order to improve readability. That is fine, although it usually makes translation memory slightly less useful (fewer matches are going to be found); the problem is that if one wants to do this, he or she should do it properly.
The way that it is often done incorrectly as in the example above (from a PC manual) is to translate the segment
"You may wish to install additional software programs or hardware devices on your PC."
"Dopo aver installato un nuovo programma software o un’altra periferica,"
and the segment
"Restart the PC after installation."
"riavviare sempre il computer."
That is, two self-contained English segments are translated by two Italian segment that cannot stand on their own ("Restart the PC after installation.
" could well be used on its own in other places, but in other instances "riavviare sempre il computer.
" would not be a correct translation for it).
The correct way to turn two sentences in the source language into one only in the target language is to:
1. Expand the segment to translate (Alt+Ctrl+Page Down in Trados) until it includes the other sentence(s) to translate
2. Translate the whole unit as a single segment
I’m finding this sort of things fairly often, and I think they pose a danger of lower quality in translation down the road.