I booked a hostel (Footprints in Singapore) through boots last week and have received the standard "tell us what you thought of your stay" email but had some trouble with placing feed back.
linking from the email I was able to give it the thumbs up but while I could type in the "comments" box on the next screen, the 'submit' button would not come live. The 'skip' button was fine, so I played around thinking maybe I had too many characters or even not enough, but to no avail so I ended up just having to give it a miss.
Then, looking on the page for the hostel, it says something along the lines of "stayed here? submit a review of this hostel" but I can't find any way to do so.
Am I missing something obvious or is there a bug?

Unfortunately, if your 'account' has already rated that hostel, then you're not able to leave another rating so not surprising you're not able to see where to add one on the hostel page.

However, you should have been able to leave your review in the first place. If I can get a few more details, perhaps I can duplicate it and find the bug.

Are you using a Mac of PC? Do you know what browser you are using (firefox, internet explorer, safari, etc) and if possible, what version of that (under the Help menu, then About)?