For the last week or so the scrollbar up/down arrows which are normally located at the top and bottom of the scrollbar have been missing. This is the case both within individual messages, and also in folders. I am still able to drag the bar to view different parts of a message or folder, but I also don't have the "fine-tuning" to scroll up or down slowly. IE If I have, for example, a folder with 1000 messages in it, then clicking within the scrollbar channel (but not on the bar itself) half-way up, would reposition the user at around message no 500. Clicking within the channel above or below the bar used to enable me to scroll by a page at a time. I lost this functionality longer ago than the disappearance of the scrollbar arrows (4-5 months at a guess), but this wasn't such an issue while I could still navigate using the up/down buttons.

Thanks in advance for any assistance.