Yes, things are getting better for IBM (NYSE:IBM), slowly but surely. Second-quarter earnings improved 17% to $1.99 billion, or $1.16 per share. And revenue grew 7% to $23.15 billion. Revenue from Global Services -- the consulting arm -- also grew 7% to $12.09 billion, while the Systems and Technology Group grew 11% to $4.43 billion, and the Personal Systems Group contributed $3.21 billion. The Personal Systems Group also had the strongest growth at 15%. Well, that's not precisely true. Enterprise Investments grew 19%, but it accounted for only $271 million. But another large source of volatility in revenue is still currency exchange.

That's right, currency exchange rates are (and have been) playing a larger role in IBM's revenue stream than any other single factor. The second-quarter revenue growth came in at 7%, but it would have been only a 4% improvement had it not been for a favorable exchange rate. That amounted to more than a half a billion in additional revenue from swapping currency, whether it was in transferring sales receipts back to the U.S. or being on the right side of a currency hedge. And don't be too surprised to hear that blue chips have been known to dabble in currency speculation from time to time.

But the currency benefit narrowed quite a bit from previous quarters, with only a 3% positive impact compared with an 8% improvement in revenue for the two prior quarters, 5% the quarter before that, and 7% for the second quarter a year earlier. Whether that's an indication of a trend remains to be seen.

Mind you, it's real revenues we're talking about here, but it's also important to look at the company's results from the perspective of what would the results have been if it weren't for all the extra dough they made off of swapping rupees, reals, ringgits, and rands for smackaroonies. For the reported quarter that would have been a growth rate of 4%. That's better than the 3% and 1% it would have taken in during the two previous quarters, but that's not exactly flying high.

Whether the narrowing impact of currency exchange and the increasing growth rate sans currency swapping will become a trend remains to be seen. My view is that they are not coincident and that the slow and steady improvement of the U.S. economy will improve IBM's total revenues and simultaneously gradually lift the dollar, erasing the currency benefits. So they will offset each other, meaning that you shouldn't expect stellar growth any time soon. Also, the impact of improvement in the U.S. economy should be weighted more than the negative impact of improvement in the currency. And this would likely be played out over the next few quarters.

So if you're a long-term holder of this company or have wanted to be one, you probably won't find a significantly better time to get in again for quite a while. Just don't expect barnstorming results this year or even the better part of the next.

Fool contributor Mark Mahorney doesn't own shares of any companies mentioned.