3100 connecting problems...

hey there,
i recently bought a nokia 3100, its not conneting using nokia suite, no device found it says
i tried it with the latest mobiMb software it showed good connection quality for a few seconds and then became bad on its own, i tried it on 3 more computers..only on one of them the good connection lasted a bit more longer that i could transfer some files, i replaced the cable twice (it is detected as fbus cable using com port in mobiMb) but i think thats not the problem.Its something else which iam not able to understand, has anyone of u had the same problem??

please help
thnx...
bye