excel validation lists

When I select an item in say cell A:1, based on my selection a list is presented in cell B:1 in the form of a validation list where the list values are dynamically retieved from a database. This code has worked for ages, however some of the lists are now fairly large.
I now receive the error,
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Run-time error '-2147417848(80010108)':

Automation error
The object invoked has disconnected from its clients

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If I reduce the number of items in the list then it works. So the question is is there a limit on the number of items I can have in a validation list. I don't want to use combo box objects so if there is a limit then suggestions for a better way of doing this would be appreciated. Code snippet below. red where debugger gets to.

'//strList is a comma-delimitted list of values retrieved from a db. May have up to 200 values.
strList = "1,2,3,4,5,6,7,8,9,10,11,12,13,14,15"
'Populate list with list items from db
With curValueCell.Validation
.Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, _
Operator:=xlBetween, Formula1:=strList
.IgnoreBlank = True
.InCellDropdown = True
.ShowInput = False
.ShowError = False

End With

No excel gurus out there?

I am not sure this will help but have you tried dimming the list with a larger value, I am assuming this is a vba code? in a sub routine. I am not sure what the default dimension is but it sounds like your over running it. if I understand your problem. and I am certainly no guru .. :D

Thanks for you reply,
strList is just a string that holds values retrieved from a table in a database. So I loop through the db and rather than redimming an array to store the retreived values before joining them into the string I concatenate the values directly into the string. So variable sizes should not be a problem. I have since found out that validation lists can store no more than 255 characters including the commas and cannot be increased. Why I don't know.