how to set up a tonearm/cartridge

I have a Micro Seiki RX500 TT, a SME 3012R arm, an Ortofon SPU Classic GME, and a Denon DL103-R cartridges, I'm having a distortion problem that I'd like some help with, if there a generous soul to point me in the right direction, please do so, I hear said distortion mostly when playing the last two or three tracks, and most noticeable when its a female singer.
Please help!!!
Thanks to all.
A few things to look at.

First double check that the arm is correctly aligned and the slot drilled in the correct place. If you can't get the arm aligned properly then you will have problems.

With the turntable off, place a mirror on the platter and the cartridge on the mirror. Is it perfectly perpendicular to the surface of the mirror?

Make sure that the platter is level.

Are you using anti-skate?

If memory serves, and correct me if I am wrong, the GME tracks at 4.0 grams. Do you have a stylus force guage to make sure that you are tracking at the correct downforce.
This sounds mostly like an anti-skate problem since the error is most noticeable on the inner grooves...

If the distortion is mostly in one channel, try adjusting the anti-skating as follows. If distortion in left decrease A/S, if distortion in right increase A/S. If the distortion is equal in both channels then the problem is likely with the arm/cartridge alignment (use a gauge to check this) or else the tracking force may be set too low. Good luck and please let us know what you find.
Thanks folks for your help, I will try to find the cause of the problem, please do keep sending me more ideas on how to find the remedy.
Check the following:
1. Is the turntable level?
2. Is the Armboard level (when it is not original Micro Seiki)?
3. Is your adjustment right (Pivot to Spindle)
When that is all right, then you have a problem with your Arm
The 3012 can't handle all kind of cartridges, it is not really good in energy transfer (vibrations in its bearing), normally it runs well with ultra soft suspended cartridges...when nothing helps, go for a better Design, FR-64s. That Arm is a total different chapter.
Deare Marcell728: Other issue with your Ortofon cartridge is that's a poor tracker with a low compliance: 8cu, that's why those 4.0grs on VTF.. So you can expect to have a lot better results after checking the tonearm/cartridge/TT set up.

Any bad tracker cartridge not only give us some kind of problems at the inner grooves but normally at microscopic level when reading the recorded information it can't recovery the full information due that normally because that poor traking characteristic don't stay 100% in touch with the grooves and this happen not only at the inner grooves.

Now, if that kind of sound is what you like it then that is part of the trade-offs that exist in all audio items, there is nothing perfect.

According with Ortofon specs that cartridge can ride safely at 5.0grs as top/superior VTF limit. You can try it and see what happen.

Regards and enjoy the music,

just a quick note that I have put a new video on YouTube. Once everything is ok with your deck and you have finished your work on overhang and zenith you should not forget about azimuth;)

Look here:

Hope this is not too offensive to post this here but I thought if not here where then?