Not sure if the bike is a vintage.
It is a 1998 Klein Navigator touring bike
3 x 8 speed.
The rear derailleur is a Shimano Deore 8 speed and is working fine.
​The bike has Shimano 105 integrated brakes and shifters.
The front derailleur is a Campagnolo Veloce, which is not working properly from the middle front chain ring sometimes moves the chain on the other two chainrings.
is there a incompatibility with the Shimano components.
I wish to replace it with a Shimano Deore or a 105.
What are the choices?
The frame is a Aluminum one.
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I'm not sure of the details, but I believe that MTB front derailleurs may be incompatible with road front derailleurs.

I'd limit your search to Sora, Tiagra, 105, Ultegra, etc. Also look at cyclocross components.

Your bike has indexed front shifting, where the leverage of the front derailer has to be precisely matched to the particular indexed shifter.

Is that Veloce front derailer even a triple type derailer (would have a much taller inner cage plate).

I wouldn't expect the Veloce front derailer to be compatible with the Shimano indexed triple shifter. Have you gone through a proper adjustment regimen yet?

Thank you for your replies.
The Veloce probably is not compatible with the Shimano indexed, and my Veloce isn't for a triple.
I was to the local bike co-op and bought a Ultegra triple and everything works fine.

Pretty sure that Veloce front derailleur wasn’t OEM! Campagnolo components are generally high quality even the entry level stuff BUT compatibility with other manufacturers especially with index shifters is unlikely. Glad you were able too remedy the situation 🙂

Clifford is quite correct. Shimano brifters are only compatible with Shimano road FD’s, as he notes. Those have a particularly short arm between the pivot and the cable clamp. And you’ll need to find a triple version that does NOT have a deep inner cage plate.

These are several of the reasons I greatly prefer Ergo brifters, which can be used with any FD.

Edit: looks like you figured it out!