As per title really, switch in drivers door will lock all.doors but not unlock them, which is a PITA when picking someone up as you need to reach over and open door. Did a little experiment where I removed passenger switch and connected that, that seemed to lock and unlock, I've just bought a switch from ebay and think I've been unlucky as aftwr fitting that it's just locking aswell, no unlocking!! 

So is this a common issue?

Yeah, pretty common sign that the doorlock module is starting to give up due to eol. Also, this is a very common fault on VAG products. Skoda is basically VAG parts all over. So, find out what type of doorlock you have and replace it. Most likely this will over time also effect yiur rear doorlock since they are connected. I replaced mine on a golf mk5 for just under 20 gbp each doorlockmodule. Pretty easy diy, need some special tools. But maybe superb mk2 has access by removing the outer door panel. I havent checked that out yet (golf mk5 and many other vag cars from that period has this procedure)