Tune in to correct bug frequency

Not all bugs are created equal which means that some are "more equal" than others, especially those with higher Probability / Frequency rating; but how to determine the right frequency?

Here's what we found recently:

1) One of the main product features doesn't work at all when used on a specific database / a specific SQL script; this is High severity as the core feature is broken and this is always reproducible on this specific database / script it will remain a High bug?
No, the frequency here is Sometimes or even Rarely depending on the probability that customers will use that specific database or script

2) Product functionality worked perfectly during the first few repeated tests, but then it just stopped working. After OS reboot, the same scenario repeated; this is High bug as the feature is not working but as not always reproducible it will be Medium?
In such cases you need to stick a bit more with the bug and focus on isolating the exact individual steps that led to feature no longer functioning correctly. In case you isolate the bug cause better to reproduce it more Often / Always, it may even be a High bug

3) After changing some default system settings / stopping product background service / installing 3rd party kernel mode driver, our product stops working correctly and throws errors = High severity; this is easily reproducible in 100% of cases when following the exact steps which means frequency is Always?
Ask yourself how many customers will do what you just did - hack or tweak a default system or software installation or install that specific 3rd party software; the answer is very few, including those power users who like to play with everything - this is the actual probability of someone repeating those steps and it matches Rarely / Sometimes frequency corresponding to a Low/Medium bug

4) There are several UI standard violations on the main Options dialog as standard buttons are missing - this is Low severity and it is obviously reproducible always so this is a Medium bug?
Yes, but your reasoning is not right - although a Low severity issue it will be encountered by majority of the customers as present on high profile product dialog which then makes the frequency Often / Always

5) Several icon inconsistencies on the main product window when compared to other products - Low severity but this will be seen by all customers as this is on the main product window so Medium bug?
Recheck this - icons are on the main window but are you that certain that the majority of the customers will actually notice slightly different icons and text in the main menu / ribbon bar compared to other products? I say this will be noticed Rarely if at all

To summarize: frequency/probability should be interpreted with some thought vs. literal assumption that if the icon is "always different" or the button is "always missing" it corresponds to 100% or Always frequency