VMware continues to have a rough year.First, VMware posted a lackluster Q4 2007 quarterly report Jan. 29 which caused the paper value of the company to drop a whopping $8 billion in a matter of hours in after-market trading.In June, super IT power Microsoft became a major competitor with its new Hyper V virtualization platform. Then, VMware lost its CEO, Diane Greene, in a sudden corporate shakeup by its parent company, EMC, on July 8. Shortly thereafter, its next quarterly financial report also wasn't quite up to expectations.Last month, VMware issued a warning to customers about the v3.5 update to its bread-and-butter ESX hypervisor that it could cause system disruptions due to virtual machines failing to power on.Now it has lost its director of research and development after a mere nine months on the job.VMware's Richard Sarwal announced his resignation from his $1.25 million-per-year job Sept. 2, saying he will return to Oracle. Sarwal had moved to VMware from Oracle in December 2007.Paul Maritz, the current VMware president and CEO, said in a perfunctory statement that "we thank Richard for his service and we wish him well in the future. I expect to announce organizational changes to replace Richard in due course."VMware CTO and Senior Vice President of R&D Stephen Herrod will assume day-to-day responsibilities for VMware's research and development organization until a new administrator is hired. Herrod has been with VMware since 2001.Maritz, who replaced Greene, previously was EMC's head of cloud computing. Before that, he was one of Microsoft's top executives.A call to Oracle this morning revealed that Sarwal is not yet on the company's telephone list. A call to VMware was not returned today.For more perspective, see John Hazard's blog, "First Read."