alex..
I spoke with ryan_cupra today, have a word with him, basically he had similar issues and it was his ECU, he had rough running, rough idle, no faults, the same ignition fault you had, misfiring, rev high and it cuts out (like you said hooch experienced) The dealer blamed it on his MAF and coils etc, turned out to be the ECU (that water i noticed today certainly wont haver helped matters!)
He took his ecu apart and the main board was corroded inside (need new one or cleaned, but i will hassle this bloke for the other one i told you about)
Would get it checked by somebody asap, dealers they will want about 500 quid for a new one, but id be looking for a second hand one if i was you.
Vag-tech will find the fault for you, apparently hes had a few
ibiza ECUs go before! so has revo kev etc
Flashy