A week that began inauspiciously for BP after the collapse of its deal to sell its stake in Argentina 's Pan-American Energy has ended somewhat more positively for the U.K. oil giant on news that a Siberian court has found in its favor and dismissed two cases brought against it by a minority shareholder in its Russian joint venture.

So does this mean things are looking up for BP amid its ongoing Russian travails?

BP has certainly won an important battle, but the war is still far from over. This lawsuit, brought by a hitherto unknown minority shareholder in BP's Russian joint venture TNK-BP, related to its failed attempt to conclude a separate share swap and exploration deal with the state-owned giant Rosneft. The shareholder, Andrey Prokhorov, was claiming billions of dollars in damages for the deal's failure, saying TNK-BP had missed out on huge profits as a result. BP argued that the claim was groundless because TNK-BP had never been part of the deal in the first place. This in fact was the reason why BP's joint venture partners--the Alpha Access Renova Group--had the deal blocked back in February.

BP has been beset by many problems in
Russia since it formed TNK-BP in 2003--at one point in 2008 then-head Bob Dudley (who is now BP's chief executive) was forced to leave the country and run operations from a secret location. It has been threatened with many lawsuits and even had its offices in the county raided by police. But having its defense upheld by a Russian court is a significant victory for the British firm--and also some might say, a positive sign that Russia 's judiciary is being transparent and even handed towards foreign firms.

But this certainly doesn't mean the recriminations--and lawsuits--are in any danger of ending.

Although this claim has been dismissed, it is understood that BP's partners in TNK-BP,
AAR , are considering suing the U.K. firm for breaking the shareholder agreement when they tried to do a deal with Rosneft. There is also a TNK-BP board meeting scheduled for early December when these major shareholders may try to authorize another lawsuit by TNK-BP itself against BP, which would be another heavyweight challenge BP could do without.

So why does BP bother? Does the firm really need the headache, cost and uncertainty, not to mention the bad headlines that every Russian squabble generates?

The simple answer is that TNK-BP is rather good business for the British company and its Russian partners. TNK-BP accounts for a lot of BP production--since the
Gulf of Mexico oil spill and temporary drilling ban it has relied increasingly on TNK-BP to boost its oil output. And, it gets a hefty amount in dividends from the joint venture. Both AAR and BP have shared dividends exceeding $20 billion since TNK-BP's inception. A recent WSJ article compared TNK-BP to a squabbling old rock band, an analogy that Mr. Dudley said was one of the most appropriate he had heard yet.

Like a bunch of hoary old rock stars locked in a tour bus for one last grandstand reunion, the two sides may fight all the time, but they keep the show on the road because it's still in all their interests to do so.

With that in mind, expect plenty more fireworks to come.