When I upgraded from Ubuntu 8.4.0 to Ubuntu 8.4.1 and then to Ubuntu 8.10, I spent a great deal of time wailing and gnashing my teeth over earlier versions of VMware Workstation (6.0.3, 6.0.4, and 6.05) and patches. For example, VMware complained that the gcc C compiler delivered with Ubuntu 8.4.1 did not match the one used to compile that kernel. Other combinations of Ubuntu/VMware/patches did not compile for me. One combination compiled and appeared to install correctly but then complained that the number of the vmmon module expected did natch the vmmon module available, so VMware would not open my virtual machine. Groan.
However, I found that VMware Workstation 6.5 installed and worked with no problems, no need for patches, on Ubuntu 8.10 (Intrepid Ibex), kernel version 2.6.27 (32-bit).
I pass this experience along for those (like me) who were apprehensive about upgrading: make the big leap; forget the small, cautious steps.
Hope this helps,
Kathleen Callaway