How to reproduce:
1) Create a new Project based on Scrum process
Create a new user
Add him to the project area as team member
Set his work allocation to 50%
Create a plan for Sprint 1
Create a work item assigned to this new user and to sprint 1
open the plan for Sprint 1 and check the load bar for this user. This is correct. The total hours available are 50% of the remaining time.

2) Create a second  Project based on Scrum process
Add the same user as in 1) the project area as team member
Create a plan for Sprint 1
Create a work item assigned to the same user in this project and to sprint 1 in this project
open the plan for Sprint 1 and check the load bar for this user. It is incorrect, the  total hours available are not 50%  the remaining time even the plan from 1 and 2 have the same start and end time. The total hours available is 1 h in this plan.

This value remains 1 h until you open the user record from the plan, double click on the user from the plan. Go back ot the plan and the total hours are now correct. This remains correct in this same eclipse session.

When you log out, exit eclipse and start it again the available hour is wrong again in the second project.

What is:
The available hours in the load bar is not 50% of the time remaining. it is 1 h.

What should be:
The available hours in the load bar should be the same for plan 1 and plan 2 given they have the same start and end data and given the user is allocated 50 % to both timelines.

Workaround:
I can open the use record, edit the time allocation and save the user record. After that the time reminining in the load is permanently right.