http://en.allexperts.com/q/Pharmacy-1407/Alcoh ol-amoxicillin.htm
have a look at this, its a good answer.
freind in the trade have told me that antibiotics use to contain live anti bodies (true or false?) and the alcohol affected this.........another possible for the urban myth is that sailors were told it was dangerous to drink with antibiotics, this was becasue they were given them when they had cotracted various sexual transmitted diseases and if they got drunk they slep around more and so spread it amungst the tight knit communities around naval bases so they were not told the truth.
mobile phones....the old analogue ones could cause an earth spark from arieal to metal like cars if close enough at the time of peak transmision (sending at start of new call or answering a call) but it was very very rare. digitals have never been able to duplicate this but we are still told they might. the brainiacs program was well done. in hospitals we are told they can cause all kinds of probs, this was also true of old analogues but not digital to the extent that doctors and surgeons want the ban lfted, hope this helps