Problem flashing with 3330

[skydemon]

Ive just built a Dejan light flasher cable (versimilar to Dr Bizar's version but without mbus support) but I cant get it to work at all with my Nokia 3330. Ive tried using knok and rolis flasher 4.78 on windows XP (using userport.exe as well) with no luck. For the cable im using just standard hook up wire with no shielding which is about 30cm long. Could this be causing the problem (due to interference?)

Any help is appreciated

Cheers