Their open source strategy just doesn't seem that solid to me. It seems something that is a bit on-again off-again and is not driven by some kind of guiding principle. It's not as if Google gives everything of theirs away, but it's usually pretty evident where they're coming from and their decisions generally make sense to outsiders. Nokia just seems a bit ambivalent about the whole thing, and while they're definitely involved with open source, I don't get as much of a sense of them 'getting it'.
Also, 'getting it' doesn't just mean releasing a bunch of code under a nice license, it means having a sensible strategy that advances the goals of the company. For instance, Apple has a pretty good open source strategy even though they're not particularly generous with code (they basically release what they have to and not much more). It works for them and is consistent, though.
Within the past two years, Nokia has acquired Symbian and Trolltech (now Nokia's Qt division), freeing the code to these formerly proprietary projects and opening up their development processes to community contributions and scrutiny.
That's an enormous "gift" to open source, at least by the traditional metrics of LOC and market value -- Symbian has something like 40 million lines of C++ code, and Nokia acquired it at a cost of several hundreds of millions of euros. (I'm not saying that these figures are an actual indication of its worth, but the bean counters at Nokia must have been pretty shocked by this plan...)