Newsflash – Beta software is buggy.
According to ZDNet, bug reports are already flooding in for Microsoft's new Internet Explorer 7 Beta 2 Preview. Specific issues include the possibility of arbitrary code execution as well as incompatibilities with McAfee Security Center, anti-spyware programs, and online banking sites.
Software companies go through a public beta process because actively using software will discover more bugs than a development staff alone. They use the software realistically, they use it in more scenarios and they use it with more variables (software installed, sites visited, etc)
In its effort to make Microsoft look inept Slashdot and ZDNet are completely missing the point of going to beta in the first place – to find bugs. If the software was ready for prime time it would have been released already.