Yes EP oil can sometimes cause problems. But again, the bottle of oil will state if it is OK to use with bronze. The brand of gear oil I use in all of my Brit bikes says specifically on the label "it is safe to use with all yellow metals". Some other brands of EP oils make no mention of this and should be avoided.

I forgot to post this. The oil is made by a company called Sta-Lube in the USA and may not be available in Europe. There is nothing special about it and other companies make similar oil.

From their website

GL-4 Hypoid Gear Oil has low pour points and high temp properties to provide lubrication over a wide temperature range. This versatile lubricant contains anti-rust and anti-wear EP additives to provide the corrosion protection in drives and hypoid gears. It is not corrosive to copper, bronze, or other non-ferrous alloy bearings and bushings.

If touring I don't use gear oil as I don't want to have to carry another oil and use 50W motor oil. But still have to carry ATF for the primary!