???? Error using Text Field and CachedUpdates ????

Hi there, i dont know why i receive the following error message when i
use a Text field and CachedUpdates
" [Microsoft][ODBC SQL Server Driver][SQL Server] Operand Type
Clash:Varbinary is incompatible with text.".

If i dont use CachedUpdates or if i exclude the text field from the
TQuery, the problem disappear but i dont think it is the right thing to
do. By the way, to finally know that the text field was the problem
(with the clarifying error message), took me enough time to look over
the entire application.

Any help will be appreciated,
Thank in advance, Esteban.