Oracle Server version 10.2.0.5.0,
client version 10.2.0
C:\Oracle\product\10.2.0\client_1\bin\oci.dll
PL/SQL Developer 12.0.8, 32bit version
Windows7x64

When I try to debug, and I use stop over, it jumps into very strange procedures, which does not have debug information.
It also jumps into triggers bodies.
I think, it does not debugs the procedures, which is shown on the screen, because further step overs are not moving, the execution point remains in the same line.
I don't know, if if happens with every debugging session, but I saw it many times yesterday, while debugging different procedures.

I tried to revert back to 12.0.7, and it works fine.

We have had some more reports about this issue. We'll have a new fix shortly.

Anything new on that?
We encounter the same issue and reverting back to the previous version is not really an option in our organisation because it was quite old already.

You can use the current version 12.0.7. Version 12.0.8 has been retracted.