All internal errors indicate the compiler has gotten into some unstable state or some assertion is being triggered -- which means there's a bug in the compiler.
As usual we can't fix it unless you provide us with a way to reproduce it, i.e. (1) source code (preferably one preproccessed file) (2) the version of the Intel compiler you are using and (3) any compiler flags necessary to trigger the bug.
>>If I build in 32 bit mode and my app is in 64 bit mode, is this safe to do? If you mean your build development system is a 32-bit system or has a 32-bit operating system and you are trying to build a 64-bit target, then yes; it is fine to do so. You can cross build 64-build binaries on a 32-bit system.
This issue has been resolved in the parallel Studio 2011 XE (containing compiler version 12.0) that was released yesterday. The fix has not been incorporated intot he 11.1 compiler due to potential sideaffects it might cause.