Weird problem, boost doubles after battery ground has been removed

Using MMCflash to read/write the ROM-file, tried to modify the file with ECUflash but as per other thread I still have the wrong definition file, so I reverted to the original file (which is apparently a stage 1 tune as I can see some parameters have been modified).

The car hit about 0.6-0.7bar boost, and ran pretty smoothly. See the Oct12 logfile below.

However, I removed the battery negative/ground terminal for 10 secs and put it back on, and now the boost jumps up to 1.1-1.2 bar and it runs very erratically with fuel cuts at that boost level. Also, the idle speed drops to 600rpm, which almost stalls the engine when stopping at traffic lights.

See Oct13 logfile.

I tried rewriting the ROM-file before and that fixed the problem. Then removed the battery terminal, and the problem returned. And now it seems to be a permanent error, even after rewriting the original file to the ROM.

Any idea what's causing this?

Log files if anyone cares to have a look.