Make this comment from Khun Paul a "sticky", he very lucidly points out that preparation is the key, when dealing with Thai Immigration. One pre-visit, to your office, a quick chat about "new requirements", go home and prepare and return early enough to sort out any problems that might occur.

Yes, preparation is important. Also on marriage visa, have twice had to take new house photo because told one 'not right'. So i always go early so i can get these changes done and go back 2 days later. I do give 2000 baht but i get them to do all the photocopying! Only a small tip but i get extra fast service for some reason .....