Ahmad Ibrahim, who is in charge of the channel’s Syria coverage, is the brother of Anas al-Abdeh, a leading member of the opposition Syrian National Council. He allegedly stopped using his family name to avoid drawing attention to the connection. (24.February 2012)
http://english.al-akhbar.com/node/4525/

Al Jazeera has supplied Syrian rebels with satellite communication tools to ensure telephone and Internet connection, claims Ali Hashim, a former correspondent of the Qatar-funded channel. The equipment was smuggled from Lebanon, he told RT.

In protest against its performance in covering the events in Syria and the Arab region, Managing Director of al-Jazeera Office in Beirut, Hassan Shaaban has forwarded his resignation to al-Jazeera Channel, according to Lebanese al-Akhbar Newspaper. In this context, the newspaper said that Shaaban resigned in protest against the biased and provocative policy adopted by the channel in covering the events in the Arab region, particularly in Syria and Bahrain.The resignation comes a week after the producer of the Channel's office in Beirut, Mousa Ahmad and the correspondent Ali Hashem resigned for the same reasons.

A source told the Lebanese paper Al Akhbar that Al Jazeera’s Beirut correspondent Ali Hashem had quit over the channel’s stance on covering events in Syria. "… his position [which] changed after the station refused to show photos he had taken of armed fighters clashing with the Syrian Army in Wadi Khaled. Instead [Al Jazeera] lambasted him as a shabeeh [implying a regime loyalist],” a source told Lebanese press.


Some random sources from newspaper around the world.
Google about this stuff by your own.

Prominet Al-Jazeera journalist Bin Jeddo resigns. (24. April 2011)
http://www.emirates247.com/news/world/prominent-aljazeera-journalist-resigns-2011-04-24-1.384616

Al-Jazeera exodus: Channel losing staff over 'bias' (13. March 2012)
http://rt.com/news/al-jazeera-loses-staff-335/

Ex-employee: Al-Jazeera provided rebels with satphones (04. April 2012)
http://rt.com/news/al-jazeera-rebels-phones-lebanon-281/

Al-Jazeera gets rap as qatar mouthpiece (10. April 2012)
http://www.bloomberg.com/news/2012-04-09/al-jazeera-gets-rap-as-qatar-mouthpiece.html

Side note:
Al-Jazeera female staff quit over dress code (31. May 2010)
http://www.arabianbusiness.com/al-jazeera-female-staff-quit-over-dress-code-271806.html
http://www.dailymail.co.uk/news/article-1283010/Al-Jazeera-anchorwomen-quit-newsroom-row-clothes-decency.html