I have an "O" visa which is due to expire in a few weeks however I re-entered the kingdom last week and was given 90 more days, as is the norm. It is stated that to obtain a 'retirement' visa I need to apply before my 'O' visa expires. The provincial immigration office is confused as to which date applies and were of the opinion the 90 day extension might be the appropriate time. I pointed out to them I may be leaving the kingdom in a week or two in which case my O visa would no longer be valid and I could not apply for a retirement visa (catch 22). Surely they need to issue the retirement visa 'a priori'. Does any member have any experience, views or opinions regarding this?

The extension of stay (which iswhat you want) can be applied for during the last 30 days of your permisison to stay (the stamp in your passport that tells you when you have to leave the country, which you got at the border).

In some cases, when people have a need to travel, immigration will allow you to apply for the extension early. But in your case the question is also when you will return to Thailand. If you plan to return to Thailand before the date you are curently allowed to stay, you can get a re-entry permit for 1,000 baht. The re-entry permit allows you to leave Thailand and keep you current permission to stay. It doesn't add any days, so you would have to return Thailand before your current permisison ends and apply for an extension of stay.