I suspect the reason Arab countries don't want Saddam ousted is that if he was, Iraq would soon return to being a full oil exporter, lowering oil prices for all.
I suspect there are a lot of reasons they don't want it. For all that he's an SOB, Saddam does keep Iraq relatively stable. Saddam's ouster could potentially open the way for an Islamic fundamentalist takeover, which would be bad news for the Saudis.