When overlaying AORs on full sky images, the AOR projection is not correct: this effect is more evident as the AOR is close to the map's edges.

- Implication for user: This can be important for large scan maps that can only be displayed on an all-sky image. The overlay display will not correspond to the true map area, making AOR optimisation difficult or impossible for the user.

- Recommended action: To overcome this issue, you need to use a map with a different projection, e.g. a tangential projection centered on the AORs area. If you don't have such a map or you don't know how to produce it from available datasets, please ask the HSC to provide one, specifying the centre and boundaries of the area you are interested in.

when overlaying multiple AORs (close to each other, usually having same target) on the same image, from time to time a message pop-ups saying that the specified AOR is outside the image and the user is asked if he or she wants to use a full-sky image instead.

- Implication for user: This is principally an inconvenience.

- Recommended action: The only solution is to close the image, re-download it and re-plot the AORs on it.

If an AOR is prepared with a visibility constraint and the AOR is then calculated, when that AOR is overlaid, the constrained visibility windows are retained.

- Implication for user: This is principally an inconvenience.

- Recommended action: This is principally an inconvenience to users but, if it presents a serious problem, the best solution is to select and overlay a different, unconstrained AOR, before switching back to the original to overlay.

There are display issues close to the celestial poles.

- Implication for user: This is principally an inconvenience.

- Recommended action: For AORs very close to the poles we are aware of various issues that are mainly irritations to the user, although these have been fixed progressively. These do not stop users from preparing AORs in these regions, but grid and AOR overlays should be treated with suspicion as they may sometimes be incorrect.

There are some unresolved issues of relatively minor importance with the display of moving targets. In particular, if you display a moving target with a 3-colour image background the display parameters for the first colour layer are not propagated to other layers, so you must take care to enter the some date for each layer of the image.

- Implication for user: This is principally an inconvenience.

- Recommended action: If working with a three colour plot as background, note down carefully the date that you have choosen to display so that you enter the same date and time for each layer. Alternatively, work with a monochrome image.

Buttons not visible (mainly in Mac)

Sometimes, depending on the screen resolution, some buttons on the bottom of a window may become cut out and not visible.

- Implication for user: There is no indication about this (no scroll bar is displayed) and the user cannot open an observation estimation window, or do a visibility check. This usually happens if the AOT window cannot use the whole vertical space of the screen, as in cases when there is a dock bar on the bottom. This has tended to be an issue particularly for MAC users, but can occur in pop-up windows in other Operating Systems when editing long lists of observations.

- Recommended action: To overcome this situation, a way out is to auto hide the dock, or change its placement before opening the AOT window. However, this problem should be very much reduced in importance for users in HSpot v5.0.4 and later.