Turkish word stress causes sometimes difficulties in understanding spoken language at least for me. One rule that is quite clear is that of the negative marker –mA-. It is unstressable (except in most combinations with the aorist suffix) and as a rule it causes the syllable before it to receive stress. Listen to

http://www.youtube.com/watch?v=aIWx3g5eyUU

and you will hear it in practice.

GİDERAYAK AT THE LAST MOMENT

Giderayak işlerim var bitirilecek,  -  I have things to finish at the last moment,
                                                    giderayak.  -  at the last moment.
Ceylanı kurtardım avcının elinden  -  I resqued the gazelle from the hunter’s hands
ama daha baygın yatar ayılamadı.  -  but it still lies unconscious and couldn’t come to its senses.
Kopardım portakalı dalından  -  I picked an orange from the branch
ama kabuğu soyulamadı.  -  but the hull couldn’t be peeled.
Oldum yıldızlarla haşır neşir  -  I became busy with the stars
ama sayısı bir tamam sayılamadı.  -  but their number could  never be completely counted.
Kuyudan çektim suyu  -  I pulled the water from a deep hole
ama bardaklara konulamadı.  -  but it couldn’t be poured into the glasses.
Güller dizildi tepsiye  -  Roses were arranged on a tray
ama taştan fincan oyulamadı.  -  but a stone cup couldn’t be carved.
Sevdalara doyulamadı.  -  People couldn’t get enough of passion.
Giderayak işlerim var bitirilecek,  -  I have things to finish at the last moment,
                                                    giderayak. at the last moment.

(My translation sounds lame also. Any corrections are welcomed.)

Good observation.

It (the stress moving) also gives you an idea what might be the the -ma-/-me- would be in the following:

Bil-me-den konuşma.

O gel-me-den ben gittim.

Anla-ma-dan konuşma.

We had some discussion before about that -ma- here.  Some thought/said it was the infinitive some said it was the negative veb suffix.

The stress discloses that it is the negative marker. If it was ablative of the verbal noun the word stress would be on the last syllable.

When I go I say

                            Yüzmeye gidiyorum

When I come back I should say respectively

                            Yüzmeden geliyorum

true?

But -meden has this other meaning ´without doing´. If I actually swam would it be enough to give the word stress to the last syllable or do I need to use another structure for expressing it?

Though it may not be correct 100% of the time, the second syllable in a word seems to get the stress in Turkish.

With stressed syllable in bold:

Yüzmeden geliyorum = I´m coming from swimmimg

Yüzmeden geliyorum = I´m coming (back) without swimmimg

Instead of 1st one, you can also say(and I would prefer this one as a native):

Yüzmekten geliyorum = I´m coming from swimmimg

Thank you, si++. It makes perfect sense to me. Feels so nice to understand something new.

Your last question has reminded me some old threads:

http://www.turkishclass.com/sfa/turkce/forumTitle_21679

For example see my post# 8.

Quite a useful post, thanks for the hint. It´s funny that the differences in meaning between -mAk and -mA infinitives show in ablative exactly. Maybe confusion with negative -mA has something to do with it.

Ablative carries a negative tone anyway, like in the phrase -dAn etmek ´deprive of´.

I personally think that the reader reads some weird, some (or very) unstressable  

If you say so, caliptrix. I don´t think anything, I am yabancı. I just paid attention to the stress thing while I listened to Nazım Hikmet reading his own poem here.

I heard many poem readers read weird indeed. The reader may be the poet as well. I remember that Necip Fazıl heard that someone read his poem and he said: "you have just devastated my poem". But I heard some of poems read by his own voice, I thought the same think: "he devastated the poem"

As a result; poem reading is a different thing. Everyone has his own feelings on the stress of the poem reading. Don´t get me wrong, but I personally think not everyone can read poem well, just like singing; not everyone can sing well.