Just had the same problem here, someone accidentally deleted 7000 rows from a table so i was asked to do a restore to the dev server so we could get the data back.
I set it up in Management Studio to restore to 14:48, selected the relevant logs and set it off, only for it not to stop at 14:48 and restore to the end of the last log. I set up the restore again and scripted it out rather than running it to find that there was no stopat clause, I added it myself and ran the script and the restore worked.
My boss is telling me that using point in time via management studio only works if you're restoring over the same database or on the same server as the backup was taken. In this case it was a backup from live, restored to a dev database on a dev server it didn't work. He's not great at explaining stuff so if anyone could enlighten me on this i'd appreciate it.