Hmm… I havent written in my diary for a while, so I suppose ill write something in it right now :cowboy:
I wrote this support case a while ago, but I am posting it because 1) Some of you I know have experienced this as well, and 2) They make a longass explaination for something that could take one word to say: Lag. 
Case 38215 History
2005-04-17 David Gruyé II:
hey again 
i have run into an issue when i am out skilling with my whip. i will be standing there, hitting a creature, then all of a sudden not deal damage to it for several clicks in a row. i have not moved and i am aiming at the same spot i was aiming at when i was dealing damage to it. i have to move around alot, or even run away from it for a bit in order to be able to hit it again, which only happens about 80% of the time… sometimes i cant hit it again no matter what i do…
i dont know if this is a bug or just lag (doubt it since there is nobody else on my screen and it happens quite often), but it is annoying as heck… 
Gruye
2005-04-20 MindArk Support:
Are you sure the MOB hasn’t moved a little bit? How do you do it, in first person mode? Aim mode or target mode? Is the MOB targeted(with a green box around it)? Please do submit all details you have as we cannot seem to make that happen here.
2005-04-20 David Gruyé II:
yes i am sure the mob hasnt moved because i havent moved and im just standing there tanking it.
i hit it in first person mode
aim mode (where you move the mouse to look around)
i havent targeted the mobs (the green box), just the blue one when you aim at it.
it mostly happens to cornundacaudas and Gradivores (dunno about others, exarosaur and combibo around PA are fine), and after i have been there a while. i relog when it starts happening, but that doesnt really fix it, just makes it go away for like 5min…
it might just be lag, but it happens alot so i dunno…
2005-04-21 David Gruyé II:
well if you cannot make the same thing happen over there, then it is most likely lag that is causing it. either way, its annoying…
2005-04-22 MindArk Support:
Hi,
Sometimes issues occur that are related to the PE server systems, the client, the connection, Internet as a whole, the participant’s ISP or home computer that affect performance. Our general suggestion when such incidents occur is to change location in the virtual universe to see if the issue still exists. If it does and you feel it is unacceptable we recommend you take a small break. If you have these problems often, we suggest you contact your ISP and have them check your connection for packet loss (a term used when dealing with Internet communication). Packet loss means that the data stream is disrupted and data must be re-sent from the server to the client, meaning it takes longer to register events ingame, causing “lag”.
You can also try changing the internet connection speed in the clientloader options. For dialup users, a speed of 64 or 128 is recommended (technically it uses another packet size).
For broadband users, 256k is the recommended setting since it should never be set higher than the bandwidth actually available which seldom is the speed you pay your ISP for.
We continuously monitor our connections and available bandwidth. However, lag problems often are created outside our control and mostly happens because of ISP overbooking or backbone overload. One way to test would be to use the “tracert” tool in windows2000/xp (run from command prompt) and target rp.project-entropia.com. This will show the time between you and all gateways on the internet on the way to our servers. Running this command repeatedly will give you an idea about where the lag is (the hop with most time added).
/Regards
So yeah, that was a waste of a perfectly good explaination… lol :laugh: