hugs error message

[Luba Pozlevich]

	Hello,

Can you help me, please, to solve my problem with hugs-error
message. I am writing a parser for functional language using parser
combinator library. I have hugs error message and don't know how
to correct this error.
The message  is 

Type checking      
ERROR test.hs:157 - Unresolved top-level overloading
*** Binding             : pEVar
*** Outstanding context : (Alternative b, SymParser b Token, SplitParser b, 
Sequence b)

Can you help me to get some ideas where this error is going from?
If there is no enough information to answer my question I will write more.
Thank you for your help.

-- 
Luba Pozlevich,
e-mail: luba@blackcat.pereslavl.ru