Problem to run SNOPT on Matlab R2010b

I am using SNOPT 7.2-11 on my 64 bit Ubuntu 10.10, with MATLAB R2010b. I think SNOPT alone works fine, but MATLAB has problem when calling snoptcmex, it always reports: "out of memory". I checked I have sufficient memory - 6GB. I tried to use gcc-4.4 and gcc-4.3 for the mex file, but neither of them helps. I can compile the ordinary mex file successfully, like the simple "hello world“ program.