Would you please test latest product VTune Performance Analyzer v9.1 Update 8 on supported operation systems? For example -
Ubuntu* 8.xx and 9.xx
Other thing is that you have to check supported processors as well in release notes.
Linux* kernel version 2.6.32-xx are not tested for latest product v9.1 Update 8. So the user takes risk to work on such operation systems.
If the problem was due to Sample Buffer size - I feel surprise, that default size is only 2MB. My suggestion is to enlarge Sample After Value (SAV) to reduce samples if necessary.