[kbolino]

1. The memory controller will impose its own limit, which may be less than you'd think.

2. The form factor may also impose a limit. You won't find a DDR stick larger than 1GB, for example.

Of course, if either of those were the cause of a 2GB limit, then you could make the case that the whole system should be upgraded, but that's a lot more expensive than a couple of sticks of RAM.