Using Firefox but wouldn't work in IE either. The problem seems to be when you set up a field and save it as a non fee field. Then go back and change it to a fee field and it will not charge the fee. Recreate it by copying it and the new field will charge the fee.
Can't open the site for testing right now because it is a live site.
What about the limit of only being able to display 15 fields in the events configuration?
Will test further, but thus far can't replicate it doing what you said here.
Regarding the limit, there is most definitely NOT a limit on how many fields you can use. We've seen DT Register users with crazy numbers of fields No limit is setup in the code either.
When you are on the fields tab in the event management, be aware that conditional fields will NOT show. Only the top level fields show up... when the top level field is enabled for an event, any lower level fields (conditional) are auto-enabled for the event. So not needed to show there. I'm assuming this is what you are seeing... expecting to see the conditional fields, but they're not there.
I can kind of confirm this bug although I'm finding something slightly different. I can't get the fee field to apply unless I change the field settings within the Specific Event away from Default. I am using 2.7.4 (updated from 2.7.3).
Steps to reproduce:
1) In backend, create a drop down field titled Test Fee.
2) Apply values of 10|20|30 with selection limits of 0|0|0
3) Check Fee Field and apply fees of 10|20|30. Fee type: Amount.
4) Default Settings: All Events-Yes, Show-Individual, Required-Yes, Group Registrations-Each Member
4) Save field
5) In frontend, go through registration form as individual and make selection in Test Fee field of 10, 20, or 30. The expected fee is not added.
6) In backend, select the particular event and then select Fields.
7) For "Test Fee" in "Used for this event?", select "Individual" (or "Both"). Something besides default.
9) Go through registration process again and fee is applied correctly.
In doing this testing with 2.7.4, I can't get a fee field to work unless I go into the individual event and change away from the Default option for that particular field.