I'm not sure which way you mean 'trouble' - if you mean as regarding the actual performance of the pads, quite the opposite..... I find they more than meet my needs on all counts - I am the first to admit that I'm not a professional, but my artwork still requires a fair amount of fine work. 

When I came over to the States I actually found I had forgot the driver disk for my current one - XP found it and set it up without a problem on a new system. (Granted I don't have the utilities that come with it, but it works the way it should, which is my main thing).

If you mean 'trouble' as in getting used to it, I have to say no - getting used to a keyboard is 100 times harder, imo!  The only thing I found was trying Photoshop with the pen sensetivity 'on' or 'off' for line thickness - I prefer it off, but I'm sure that's a matter of taste.

The only trouble I have using the things is keeping them to myself........

Cheers.

When you starve with a tiger, the tiger starves last.