Its recorded in many Haditsh and in Islamic history Books that Quran was revealed or existed in the time of Muhammad and after his demise in multiple forms, dialects or versions. Normally, we understand that Uthman, while facing danger of loosing Qureshi version of it, order to Burn all other copies of Quran. If Quran is revealed from Allah and if the source and recipient of Quran is one, then why we have these multiple narrations and recording of multiple version of it ?
"Bukhari :: Book 6 :: Volume 61 :: Hadith 510
Narrated Anas bin Malik:
Hudhaifa bin Al-Yaman came to Uthman at the time when the people of Sham and the people of Iraq were Waging war to conquer Arminya and Adharbijan. Hudhaifa was afraid of their (the people of Sham and Iraq) differences in the recitation of the Qur'an, so he said to 'Uthman, "O chief of the Believers! Save this nation before they differ about the Book (Quran) as Jews and the Christians did before." So 'Uthman sent a message to Hafsa saying, "Send us the manuscripts of the Qur'an so that we may compile the Qur'anic materials in perfect copies and return the manuscripts to you." Hafsa sent it to 'Uthman. 'Uthman then ordered Zaid bin Thabit, 'Abdullah bin AzZubair, Said bin Al-As and 'AbdurRahman bin Harith bin Hisham to rewrite the manuscripts in perfect copies. 'Uthman said to the three Quraishi men, "In case you disagree with Zaid bin Thabit on any point in the Qur'an, then write it in the dialect of Quraish, the Qur'an was revealed in their tongue." They did so, and when they had written many copies, 'Uthman returned the original manuscripts to Hafsa. 'Uthman sent to every Muslim province one copy of what they had copied, and ordered that all the other Qur'anic materials, whether written in fragmentary manuscripts or whole copies, be burnt. Said bin Thabit added, "A Verse from Surat Ahzab was missed by me when we copied the Qur'an and I used to hear Allah's Apostle reciting it. So we searched for it and found it with Khuzaima bin Thabit Al-Ansari. (That Verse was): 'Among the Believers are men who have been true in their covenant with Allah.' (33.23)"
However that was in the time of Uthman, He was the Political leader and was in power, He could do anything, so He did. However, what He forgot that Muhammad Himself gave permission to these "Dialects" to be used among Muslim, while reciting Quran;
"Muslim :: Book 4 : Hadith 1782
'Umar b. Khattab said: I heard Hisham b. Hakim b. Hizam reciting Surah al-Furqan in a style different from that in which I used to recite it, and in which Allah's Messenger (may peace be upon him) had taught me to recite it. I was about to dispute with him (on this style) but I delayed till he had finished that (the recitation). Then I caught hold of his cloak and brought him to the Messenger of Allah (may peace be upon him) and said: Messenger of Allah, I heard this man reciting Surah al-Furqan in a style different from the one in which you taught me to recite. Upon this the Messenger of Allah (may peace be upon him) told (me) to leave him alone and asked him to recite. He then recited in the style in which I beard him recite it. The Messenger of Allah (may peace be upon him) then said: Thus was it sent down. He then told me to recite and I recited it, and he said: Thus was it sent down. The Qur'an was sent down in seven dialects. So recite what seems easy therefrom."
The obvious question is, if Muhammad made it clear that Quran is revealed in seven Dialects, then on whose authority Uthman acted and burned all other dialects ? Was he simply refusing to accept the wisdom Muhammad had on this matter ? Or Uthman finally understood the thing, which Muhammad himself failed to realized that these different dialects in Quran would create a major problem and Quran will be lost forever ? In this case, only one of these men are correct in their understandings, I will let you decide yourself.
Apart from this problem, if we have to believe that Quran was indeed revealed in 7 Ahrufs and styles, or as we read the Islamic history even in 25 different styles of reciting or styles [The first person to record these readings in the form of a book was Abū ‘UbaydQāsim Ibn Salām (d. 224 AH). He recorded twenty five readings; Abū Ja‘far Tabarī (d. 310 AH) recorded over twenty readings, while it was Abū Bakr Ibn Mujāhid (d. 324 AH) who selected the seven famous ones] where are these reciting today and why not used by Muslims and if not, then why not ?
If Abu UbaydQasim Ibn Salam was right to pointed out 25 different different styles in the early days of Islam, then who we know that what we are today reading is the one version which revealed to Muhammad ? I am quite sure UbaydQasim was well aware of the fact that Uthman did his best to destroy all other versions, but his admission of 25 different versions in his time, is embarrassing to Muslims who claim that Quran was protected by Allah. I would like to see a logical explanation which clear that among these 25 versions, only the current versions was the true version and it survived.
Now I do understand that general answer from Muslims is that dialects does not change the substance or words of Quran and even if there were 25 versions or style of Quran, they were all same. I would like to point out that Arabic as you all Muslim know, some time a minor change in sound can change the whole word and its meanings. My response is simple, look what Uthman did, if He knew that fact which we hear from Muslims, there was no need to burn all other manuscripts, He did because He knew it will completely changed the Quran if not stopped here finally. So where are these 25 or 20 or 10 or 7 versions and what was so wrong with them that they had to go ?