As for Rush Limbaugh - just check his website and transcript for the full context. At no time did he say not to donate to Haiti. Indeed, other of Rush's comments were about how if the US takes away the tax deduction for charitable donations the ability of American's to contribute will be diminished.
As for the basket case that is Haiti? Predictably there are those who will try to blame everything but the real issues (e.g. Bush, capitalism, the UN, the US generally. . .and even the failure of the Copenhagen climate summit).
The main problem is corruption. Haiti remains one of the most corrupt countries in the world.
Should wealthy nations help? Yes. Should the US do what it can to get aid to those who need it? Of course.
Should the US right be blamed for trying to block such assistance? Of course not. At least not based on the facts of what conservative opinion leaders are actually saying and doing.