EDIT: Upon further research, it seems the salary situation in Astana 2007 & 2008 was non orthodox to say the least. So Biver might not be responsable for this, contrary to what was written in this message. More details in another message down below.
How was the Astana team built?
My understanding is that it's the continuation of the Liberty Seguros team which was not allowed to start the 2006 tour since they didn't have enough riders available (the rest kicked due to Puerto links). The Kazakh cycling federation ponied up the dough to keep the team going as a vehicle for Vinokourov to win the TdF - for make benefit glorious nation of Kazahkstan!
Astana-Wurth was indeed ONCE/Liberty-Seguros. Astana became the sponsor of the team after the Puerto scandal (which involved Manolo Saiz), but the team management was done by Active Bay, Saiz's company.
But Active Bay's ProTour licence was discontinued for the 2007 season, for reasons somewhat unclear to me. When Puerto hit, UCI was "sorry" that they could not withdraw it, but the 2007 ruckus seems more financial than related to doping: Saiz deplorable image didn't help, but I think the idea is that the kazakh sponsors wanted a more direct control, Saiz wouldn't let them get any share of that despite the fact he needed some financial back-up to get the PT licence. It is my understanding the sponsor decided to apply for a PT licence with another partner. (see here
for a perhaps clearer summary)
So in 2007, team Astana was actually a different, new structure. The management was done by company Zeus, belonging to Marc Biver.
The string of doping scandals pushed Astana to demote Biver.
At the same time, Discovery was living its last season as the sponsor annouced they wouldn't back the team any more.
By the end of season 2007, Astana and Bruyneel (with Disco remains) decided to associate.
So Astana in 2008 & 2009. Management company is Olympus belonging to Bruyneel, located in Luxemburg.
Bruyneel has announced that he and Astana will part as he follows Lance to Radio Shack in 2010.
In 4 years, "Astana" was actually 3 distinct legal entities, located in three different countries. Apparently, the riders are contracted to Olympus and not "Astana" in Kazakhstan. Olympus is in charge of all the management (car, salaries, etc...). And we know that for 2010, the management will change again.
Everything points out it was the same before: Astana 2006 was basically Liberty Seguros, so Saiz held the contracts. Zeus was supposed to manage the team in association with Astana up until 2010.
Now consider that Vinokourov was suspended in 2007. At that time, it makes sense he was under contract with Zeus/Biver. After 2 years, it is likely his contract went to its term (or was terminated by his suspension). JB had no reason to contract a suspended rider (I am not sure you are allowed to do that anyway...).
In this situation, contracting Vino might be easier said than done. Are you allowed to sign a rider for only a couple months? Can Vino runs for Astana while not being contracted to the management company? I don't know. It has been said that Vino should run the Vuelta with Astana, so maybe they sorted it out. But legal reasons might force Vino to wait a certain date before being part of the Astana roster for the end of the season.