No you really didn't do any thing wrong....
Just need to make a couple changes to the macro....
When you recorded the macro it should look like this:
Use Item
Use skill / Cast Spell
Target
Target
Here's how you change the things...
Highlight Use Item.... Right Click and choose Convert to Use Item Type
Use Skill / Cast Spell .... leave as is
Highlight the 1st Target .... Right Click and Choose Convert To Target Type
The Last Target is Fine, but I would change it as above so it works on any dagger.
When you done, your macro should look like this....
Use Item Type
Use Skill / Cast Spell
Target Item Type
Target Item Type
Set your macro hot key and your ready to roll. If you are adding multiple instances, you will need to add a delay in after you poison the dagger and make the changes as above.
The reason for making these changes is everything in UO has a unique ID. So, the first time you made the macro. It basically said....
Use this Keg - (Would work until you needed a new keg)
Use This skill
Use this potion - (That exact potion no longer existed once you used it)
Use This dagger - (could never switch daggers, which is fine, but it's just as easy to do any dagger)
The changes make it say....
Use any keg (of this poison type)
Use this skill
Use any bottle (of this poison type)
Use any dagger
Now as you switch thru the different levels of potions, you will have to right click on the sections you made changes on and choose Reset Item & Reset Target. When you reset the item / target it brings up the targeting curser. Just choose the new level of poison keg and the new level of poison bottle.
That will allow you to use the same macro for lesser posion all the way thru Deadly poison.
Hope that helps,
Q